Easy 4-Ingredient Slow Cooker Sausage and Onions

This comforting 4-ingredient slow cooker sausage and onions is the answer to those insanely busy weeknights. You can have it prepped in just a few minutes, put it in the crockpot and then run out the door. When you get home, your house will smell like an Italian restaurant.

Since it only has a few ingredients, there’s no panic-inducing dash to the grocery store. You can serve it over noodles, in a hoagie roll, or just eat it out of a bowl. It’s incredibly versatile and delicious!

Why You Will Love This Recipe

You’ll be in love with how soft and succulent the sausage gets when it simmers all day. The sweet onions will break down in the slow heat and turn into a rich, tasty gravy. Every bite tastes like a slow cooked meal without the actual effort.

The best thing about this meal is how little cleanup there is when you’re tired. There are no greasy pans to wash since the slow cooker does all the work. This is the perfect solution for a crazy Tuesday when you need everyone to have dinner.

The Ingredients

Here’s what you’ll need to make this super easy crockpot meal: raw Italian sausage links, sweet yellow onions, green bell pepper and your favorite marinara sauce.

Italian Sausage Links

These plump sausages are the star of this dish, adding garlic and herbs to the entire recipe. Use mild, sweet or hot links, whatever your family likes best. Keep them whole so they remain moist. If you don’t eat pork, try chicken or turkey sausage for a lighter option.

Sweet Yellow Onions

I love yellow onions in this recipe because they get soft and sweet. I recommend slicing them into thick slices so they maintain a bit of texture after all that slow cooking. If you don’t have any yellow onions on hand, white or regular yellow onions will work just fine, although they may be a little more pungent.

Marinara Sauce

Using a store-bought jar of marinara sauce is one of the quickest ways to make a rich and flavorful base. It adds a nice, bright, slightly acidic broth that keeps the sausage and veggies moist and tender throughout the entire cooking process. If you don’t have any marinara sauce available, crushed tomatoes seasoned heavily with Italian seasoning and garlic powder will work in a pinch.

How to Make It

I’ll show you exactly how easy this dump-and-go slow cooker recipe is to prepare.

Prep the Veggies

Cut the sweet onion and green bell pepper into large, even pieces and spread them out in a single layer at the bottom of a greased slow cooker.

Add the Sausage

Place the Italian sausage links in a single layer on top of the vegetables. Try to avoid overlapping them too much so that they can cook more evenly.

Pour the Sauce

Pour the entire jar of marinara sauce over the sausage and vegetables and spread around a bit with a spoon so that everything is coated.

Slow Cook

Cover the slow cooker and cook on low for 6-8 hours. Alternatively, you can cook on high for approximately 4 hours.

My Best Tips for Success

If you prefer to have a crispy, slightly chewy exterior on your sausage, quickly brown the links in a hot pan for 3 minutes before placing them in the slow cooker. This step helps lock in the juices and creates a deliciously textured casing but isn’t necessary if you’re pressed for time.

Make sure that you cut your vegetables into large chunks, rather than dicing them finely. They will be cooking in a hot liquid for quite some time, so small pieces will break down into a soft, unappealing consistency. Large chunks will retain a nice texture in the finished dish.

If you find that your sauce looks a bit watery after cooking, leave the lid off the slow cooker for the last 30 minutes of cooking time. This will help the vegetables’ released moisture evaporate and give you a thicker sauce.

Storage and Reheating

• To Store: Cool the sausage and vegetables to room temperature, then transfer to an airtight container and refrigerate for up to 4 days. 
• To Freeze: Cooked leftovers may be stored in a well-sealed container in the freezer for up to 3 months, perfect for meal prep!
• To Reheat: Gently reheat the sausage in a skillet or microwave until hot, adding a small amount of water if the sauce has thickened too much.

What to Serve with This Sausage

• Serve stuffed inside toasted, crusty hoagie rolls, then covered with provolone cheese.
• Serve atop a bed of pasta, such as penne or rigatoni, to catch the extra sauce.
• Spoon onto creamy mashed potatoes or buttery, cheesy parmesan polenta.
• Serve alongside a simple salad and warm, garlic bread for dipping.

Frequently Asked Questions

Can I use pre-cooked smoked sausage?

Yes! Kielbasa or chicken sausage works great. Since it is already fully cooked, you can cut the cooking time down to 4 hours on low to simply heat everything through and make sure the vegetables are soft.

Can I cook this on high?

Yes! If you’re starting dinner a bit later in the evening, just turn your slow cooker on high and cook for 3-4 hours. It’ll still be nice and tender!

Do I need to add water or broth?

Not at all! The onions and bell pepper will release their own moisture while cooking, which will thin out the marinara nicely.