Easy Slow Cooker Italian Sausage and Peppers

Slow cooker Italian sausage and peppers is one of those meals that asks very little from you on a busy day. Juicy sausage, soft bell peppers, and onions simmer in a tomato-based sauce until everything is tender and flavorful. It is a simple dinner that works well on its own or served over pasta, rolls, or crusty bread.

Why You’ll Love This Recipe

• Hands-off cooking: Most of the work happens in the first 15 minutes, then the slow cooker does the rest.
• Simple ingredients: You only need sausage, peppers, onion, garlic, marinara, and a few pantry seasonings.
• Easy to adjust: Choose mild, hot, or sweet Italian sausage to match your family’s tastes.
• Flexible serving: Serve it on rolls, over pasta, or with a side of rice.

Ingredients

• 1 1/2 lb (680 g) Italian sausage links, mild, hot, or sweet
• 2 large bell peppers (red, green, or yellow), seeded and sliced into strips
• 1 medium yellow onion, thinly sliced
• 3 cloves garlic, minced
• 1 (24 oz / 680 g) jar marinara sauce
• 1 tsp (about 2 g) dried Italian seasoning
• 1/2 tsp (3 g) salt, plus more to taste
• 1/4 tsp (0.5 g) black pepper
• 1 tbsp (15 ml) olive oil, optional, for browning
• Pinch red pepper flakes, optional

Ingredient Notes

Italian sausage gives this dish most of its flavor. Pork sausage with fennel is the classic choice, and you can use mild, hot, or sweet depending on your preference. Sausage links with casings tend to hold their shape better than loose sausage meat.

Bell peppers become soft and sweet during slow cooking. Red and yellow peppers add a little more sweetness, while green peppers have a slightly bitter edge that many people enjoy in this dish.

Marinara sauce is the base of the dish. Choose one you already like the flavor of, since it will be the main taste in the finished meal. If your sauce is very thick, add a few tablespoons of water to keep the mixture from scorching at the bottom of the cooker.

Equipment You’ll Need

• Slow cooker (4 to 6 quart)
• Large skillet, optional, for browning the sausage
• Cutting board and sharp knife
• Instant-read meat thermometer
• Tongs or a slotted spoon

How to Make Slow Cooker Italian Sausage and Peppers

1. Prep the vegetables. Remove the stems and seeds from the bell peppers, then slice them into strips about 1/4 inch (6 mm) thick. Thinly slice the onion and mince the garlic.
2. Brown the sausage (optional). Heat the olive oil in a large skillet over medium heat. Add the sausage links and cook for 5 to 7 minutes, turning occasionally, until the outside is browned. The inside does not need to be cooked through yet. Browning adds flavor, but you can skip this step if you are short on time.
3. Layer the slow cooker. Spread the onion and peppers across the bottom of the slow cooker. Place the sausage on top. Add the garlic, Italian seasoning, salt, black pepper, and red pepper flakes if using.
4. Add the sauce. Pour the marinara over everything. Gently stir so the peppers and onions are coated, but keep the sausage mostly on top.
5. Cook the dish. Cover and cook on low for 6 to 8 hours or on high for 3 to 4 hours. Cooking times vary by slow cooker, so start checking at the earlier end of the range.
6. Check for doneness. The sausage is done when an instant-read thermometer inserted into the thickest part reads 160°F (71°C). The peppers should be very soft, and the sauce should be bubbling gently around the edges.
7. Taste and adjust. Remove a sausage and cut it open to check that the center is no longer pink. Stir the sauce, then taste it. Add salt or pepper flakes if needed.
8. Serve. Slice the sausage into thick rounds or leave the links whole. Spoon the peppers and sauce over the top and serve right away.

Pro Tips for the Best Results

• Cut the peppers into large, even strips so they soften at the same rate and do not turn to mush.
• Browning the sausage first gives a deeper flavor and a more appealing color, but it is optional.
• Do not add fresh basil or other delicate herbs until the end, so they keep their bright flavor.
• If the sauce looks too loose at the end, uncover the cooker and let it cook on high for 15 to 20 minutes to thicken.
• Use a cooker size that is at least half full but not overflowing for even cooking.

Common Mistakes to Avoid

• Skipping the thermometer: Sausage sizes and cookers vary. Checking the internal temperature is the most reliable way to know when it is done.
• Adding too much liquid: Peppers and onions release water as they cook. Using a full jar of sauce plus extra broth can make the dish watery.
• Overcooking on high: Cooking on high for too long can make the peppers very soft and the sausage tough. Start checking early.
• Using frozen sausage: Thaw sausage in the refrigerator before cooking so it heats evenly and reaches a safe temperature.

Variations and Substitutions

• Chicken sausage: Use fully cooked or raw chicken Italian sausage. Cook raw chicken sausage until it reaches 165°F (74°C), and reduce the cooking time if the links are already cooked.
• Add potatoes: Add 1 lb (450 g) of baby potatoes cut in half at the bottom of the cooker for a heartier meal.
• Extra vegetables: Add sliced mushrooms during the last hour of cooking for more savory flavor.
• Spicy version: Use hot Italian sausage and add an extra pinch of red pepper flakes.
• Sandwich style: Slice the sausage and serve the peppers and sauce in toasted hoagie rolls.

Serving Suggestions

Serve this dish with crusty Italian bread for soaking up the sauce. It also goes well with cooked pasta such as penne, rigatoni, or spaghetti. For a lighter meal, serve it over polenta or with a simple green salad dressed in olive oil and lemon juice.

Storage and Reheating

Let the dish cool slightly, then transfer leftovers to an airtight container. Store it in the refrigerator for up to 3 to 4 days. To reheat, warm it in a saucepan over medium-low heat, stirring occasionally, until it is hot all the way through. You can also microwave individual portions, stirring halfway through. Freezing is possible in a freezer-safe container for up to 2 to 3 months, though the peppers may soften more after thawing.

Frequently Asked Questions

Can I make slow cooker Italian sausage and peppers ahead of time?

Yes. You can prep the peppers, onions, and garlic the night before and store them in the refrigerator. Assemble the dish in the morning and start the cooker when you leave for the day.

Do I need to brown the sausage first?

No, browning is optional. It adds color and a deeper flavor, but the dish will still be delicious if you skip it.

How do I know when the sausage is done?

Check that the internal temperature reads 160°F (71°C) with an instant-read thermometer. The center should be fully cooked with no pink color.

Can I cook this on high to save time?

Yes. Cooking on high usually takes 3 to 4 hours. Check the sausage early and the peppers for tenderness, since every slow cooker heats differently.

Why did my peppers turn out mushy?

Peppers can break down if they cook too long or if they were cut very thin. Try larger strips and check the cooker about an hour before the suggested end time.

What should I serve with Italian sausage and peppers?

Crusty bread, rolls, pasta, or polenta all work well. A simple green salad makes a nice side dish.