Step 1

Heat 2 Tbsp. olive oil in a large nonstick skillet over medium-high heat. Add the onions; cook, stirring occasionally for ~5 minutes.

Step 2

Add the chopped bell peppers and continue to cook for another 5 minutes, stirring occasionally.

Step 3

Add the garlic, fennel seeds, Italian seasoning, salt, pepper and red pepper chili flakes if desired. Stir until fragrant, ~1 minute.

Step 4

Push the onions and bell peppers to one side of the skillet to make room for the sausage.

Step 5

Add the sliced chicken sausage rounds and remaining olive oil and cook for ~5 minutes until sausage browns on each side.

Step 6

Stir together cooked sausage and bell pepper and onion mixture. Add in crushed tomatoes. Bring to a boil; then reduce heat to medium-low and simmer for 5 minutes. Taste, and adjust salt and pepper if needed.

Step 7

Serve over cooked spaghetti pasta (or pasta of choice). Garnish with parmesan cheese if desired.