Begin by heating a large nonstick pot or Dutch oven over medium to medium-high heat. Pour in a couple of tablespoons of olive oil and let it warm until shimmering.

Cut the sweet Italian sausage in half, then add it to the hot pot. Sear the sausages for about 1-2 minutes on each side until all surfaces are golden brown.

While the sausages cook, slice your bell peppers and onions into thin strips. Keep the sausages in the pot as you add these colorful veggies.

Layer the sliced bell peppers and onions over the browned sausages. Pour in the diced tomatoes and season with Italian seasoning, salt, and pepper. Stir everything together.

Cover the pot and reduce heat to medium-low. Allow to simmer for about 20 minutes until bell peppers are tender and sausages are cooked through.

Once the dish is cooked, remove the lid and sprinkle fresh parsley over the top if desired. Serve immediately.