Slow Cooker Italian Sausage, Peppers and Onions brings savory sausage, sweet peppers, and soft onions together in a simple tomato sauce. Everything cooks in the same pot, with no skillet step to work around. The links stay whole and juicy while the vegetables soften into the sauce. Serve it with crusty bread for an easy dinner that needs very little hands-on work.
Why I Love This Recipe
This is the kind of dinner that makes good use of a slow cooker. The sausage seasons the vegetables as it cooks, so a short ingredient list still gives you plenty of flavor. There is no need to brown the links first, and the small amount of tomato keeps the peppers and onions from getting lost in a heavy sauce.
- Simple prep: Slice the vegetables, stir the sauce, and add the links.
- A balanced bite: Sweet peppers and onions soften the rich, savory sausage flavor.
- Flexible heat: Mild or spicy pork Italian sausage works with the same method.
- Useful leftovers: The sauce keeps the sausage moist when reheated gently.
What You’ll Need
- Servings: 6, with 1 sausage link per serving
- Prep Time: 15 minutes
- Cook Time: 5–6 hours on LOW, or 3–4 hours on HIGH
- Total Time: 5 hours 15 minutes–6 hours 15 minutes on LOW, or 3 hours 15 minutes–4 hours 15 minutes on HIGH
- Slow Cooker Size: 6-quart oval slow cooker
Ingredients:
- 1 1/2 lb fresh pork Italian sausage, about 6 links, mild or spicy, fully thawed
- 2 large red bell peppers, about 12 oz total, cored and cut into 1/2-inch-wide strips
- 1 large yellow bell pepper, about 6 oz, cored and cut into 1/2-inch-wide strips
- 2 medium onions, about 12 oz total, peeled and cut into 1/2-inch-wide strips
- 3 garlic cloves, minced
- 1 can (15 oz) crushed tomatoes, with no added salt
- 1 tablespoon tomato paste
- 1 teaspoon dried Italian seasoning
- 1/4 teaspoon fine salt
- 1/4 teaspoon ground pepper
Use fresh, raw pork sausage rather than smoked sausage. Choose links of roughly the same size so they finish at about the same time. No broth or water is needed; the vegetables release plenty of moisture.
Tools You Need
- 6-quart oval slow cooker with a black oval ceramic crock and lid
- Wooden cutting board and sharp kitchen knife
- Small glass mixing bowl
- Measuring spoons
- Spoon and tongs
- Instant-read meat thermometer
How to Make Slow Cooker Italian Sausage, Peppers and Onions
Keep the sausage whole and let the slow cooker do most of the work.
Step 1: Add the Vegetables
Place 2 large red bell peppers, cut into 1/2-inch-wide strips, 1 large yellow bell pepper, cut into 1/2-inch-wide strips, and 2 medium onions, cut into 1/2-inch-wide strips, in the 6-quart oval slow cooker.
Spread them into an even bed. The vegetables go underneath the meat so they soften in the cooking juices.
Step 2: Mix the Tomato Sauce
Stir 1 can (15 oz) crushed tomatoes, 1 tablespoon tomato paste, 3 minced garlic cloves, 1 teaspoon dried Italian seasoning, 1/4 teaspoon fine salt, and 1/4 teaspoon ground pepper together in a small glass bowl.
Mix until the tomato paste is fully blended. The sauce should look thick and pulpy at this stage.
Step 3: Layer the Sausage and Sauce
Arrange 1 1/2 lb fresh pork Italian sausage, about 6 whole links, over the vegetables. Do not pierce the casings.
Spoon all the prepared tomato mixture over the links and vegetables. Leave the layers in place rather than stirring.
Put the lid on right away and start cooking. Use fully thawed sausage, as recommended in the [USDA slow cooker guidance](https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/slow-cookers-and-food-safety).
Step 4: Cook Until Tender
Cook covered on LOW for 5–6 hours or HIGH for 3–4 hours, until the peppers are very soft and the onions are translucent and collapsed.
Check the thickest part of several links with a meat thermometer. Pork sausage must reach 160°F (71°C); this is the [USDA safe temperature for fresh pork sausage](https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/meat-catfish/sausages-and-food-safety). Keep cooking if needed, regardless of the clock.
Gently turn the links and stir the vegetables into the sauce once cooking is complete. The sauce will be warm brick-red, opaque, and lightly thickened but spoonable, with fine tomato pulp and herb flecks. It should lightly coat the food, with a shallow layer of juices beneath.
Step 5: Plate and Serve
Divide the 6 cooked sausage links and all the saucy peppers and onions among 6 plates, giving each plate 1 whole link and an equal share of vegetables.
Spoon the cooking sauce over the sausage and vegetables to keep them moist. Leave the links whole for serving.
Serve with crusty Italian bread alongside to soak up the juices. The bread is an optional serving side.
Why This Recipe Works (Quick Science)
Gentle, moist cooking softens the peppers and onions while the sausage releases savory juices into the tomato mixture. Keeping the casings intact helps the links hold their shape. The vegetables supply liquid as they soften, so adding broth at the start can leave the sauce too thin.
Tomato paste adds body without a separate sauce-reducing step. The finished sauce is still light enough to spoon, rather than a heavy coating. Stop cooking when both the sausage temperature and the vegetable texture are right; extra hours can split the casings and make the meat less juicy.
Common Mistakes to Avoid
- Adding water or broth: The peppers and onions release liquid on their own.
- Piercing the links: Keep the casings intact so the sausage holds together and loses fewer juices.
- Expecting a browned crust: This method gently cooks the links in sauce. Their surfaces stay soft and moist.
- Checking only the clock: Slow cookers vary. Check both the sausage temperature and the vegetables.
- Lifting the lid often: Let the cooker hold its heat during the main cooking time.
- Adding extra salt at the start: Sausage brands vary widely in saltiness. Taste the finished sauce before deciding whether it needs more.
What to Serve With Slow Cooker Italian Sausage, Peppers and Onions
Crusty Italian bread is a simple match for the sausage and saucy vegetables. Serve a thick slice alongside each plate so the juices have somewhere to go.
For a different meal, spoon the sausage and vegetables over cooked pasta or creamy polenta. These are optional serving ideas and are not included in the nutrition estimate.
Make-Ahead Tips and Storage
Slice the peppers and onions ahead and refrigerate them in a covered container. Keep the raw sausage in a separate sealed container, and prepare the sauce separately. Assemble and start cooking when you are ready rather than leaving raw ingredients at room temperature.
Refrigerate leftovers in shallow, covered containers within 2 hours. Keep for 3–4 days at 40°F (4°C) or below, or freeze for up to 2 months for best texture. Thaw overnight in the refrigerator.
Reheat portions with their sauce in a covered saucepan over gentle heat until the sausage reaches 165°F (74°C). Follow the [USDA leftover handling guidance](https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/leftovers-and-food-safety); use the stove or microwave to reheat rather than reheating cold leftovers in the slow cooker.
Macros Information
Estimated per serving, based on 6 servings, without bread or other sides:
- Calories: 390
- Protein: 20 g
- Carbohydrates: 16 g
- Fat: 27 g
- Saturated Fat: 9 g
- Fiber: 4 g
- Sugar: 9 g
- Sodium: 850 mg
These values are estimates and will vary with the sausage brand and exact vegetable sizes.
Frequently Asked Questions (FAQ)
Q: Do I have to brown the sausage first?
A: No. This recipe starts with raw, thawed links and cooks them directly in the sauce. The finished surface will be soft rather than browned.
Q: Can I use spicy Italian sausage?
A: Yes. Spicy and mild fresh pork Italian sausage both work. Choose whichever heat level you prefer.
Q: Can I put frozen sausage in the slow cooker?
A: Thaw it fully in the refrigerator first. The cooking times here are for thawed links.
Q: Can I use green bell peppers?
A: Yes. Replace a red or yellow pepper with a similarly sized green pepper. The dish will taste a little less sweet.
Q: Should I cut the sausage before cooking?
A: Leave the links whole. That helps them keep their shape and makes it easy to give each serving a full link.
Q: Why is there more liquid than I expected?
A: Peppers, onions, and sausage all release juices. Use crushed tomatoes and tomato paste as written, and skip added broth. The sauce is meant to be spoonable, not thick like a paste.
Q: Can I double this recipe?
A: Only if your cooker can hold the larger batch within its recommended fill limit. Do not pack it to the rim, and check doneness rather than assuming the same cooking time.
Q: Can I use chicken or turkey Italian sausage?
A: Fresh poultry Italian sausage can work, but it needs to reach 165°F (74°C). Check the label and use a thermometer; leaner links may be less juicy.
Q: Can I make sandwiches with the leftovers?
A: Yes. Reheat the sausage, peppers, onions, and sauce, then tuck them into sturdy split rolls. Drain off excess juices first so the bread holds together.
Final Thoughts
Slow Cooker Italian Sausage, Peppers and Onions makes a comforting dinner from a few everyday ingredients. Keep the links whole, let the vegetables soften, and save that sauce for the bread. Leave a comment with your favorite way to serve it.
Happy cooking!