Heat a large skillet with 1-2 tablespoons of olive oil. Add the Italian sausage. Chop with a large wooden spoon to break into small pieces.
1-2 tablespoons olive oil, 1 pound Italian sausage
When the sausage is mostly browned, add the onions and cook.
1 medium onion
Drain off any excess grease from the sausage.
Add the garlic and saute until fragrant.
2 teaspoons garlic
Add the canned tomatoes, tomato sauce, and tomato paste to the crock pot. If using whole tomatoes, break them up into smaller pieces. Use a potato masher, or use clean hands.
Add seasoning, cooked sausage, and onions, and one tablespoon of brown sugar. Stir together.
1 tablespoon dried parsley, 1 teaspoon dried oregano, 1 teaspoon dried basil, ½ teaspoon dried thyme, ½ teaspoon dried marjoram, ½ teaspoon fennel seed, 1-2 tablespoons brown sugar
Turn the crock pot to low and place the lid on top. Cook on low for 6-8 hours.
Taste sauce. Add a tablespoon of brown sugar if the sauce is too acidic. Add extra salt if needed.
Serve hot over pasta.
Video
Notes
Brown the sausage first – This adds a richer flavor and helps remove excess grease before slow cooking.
Use quality canned tomatoes – Good tomatoes make a big difference in taste and texture.
Chop onions finely – They’ll soften as they cook, but smaller pieces blend into the sauce more smoothly.
Add tomato paste for thickness – It deepens the tomato flavor and helps the sauce cling to pasta.
Remove excess grease – After browning the sausage, drain off any extra fat to keep the sauce from becoming too oily.
Let it cook low and slow – The longer the sauce simmers, the better the flavors come together.
Taste and adjust seasoning – Before serving, give the sauce a taste and add salt, pepper, brown sugar, or extra herbs if needed. Salt and pepper are not listed in the ingredient list, but may be added according to your liking.