INSTRUCTIONS:
Preheat your oven to 400°F.
In a large mixing bowl, combine the sliced bell peppers, sliced onion, minced garlic, diced tomatoes (with their juices), olive oil, Italian seasoning, salt, and pepper. Toss everything together until well coated.
Place the Italian sausage links in a single layer in a baking dish or roasting pan.
Pour the pepper and tomato mixture over the sausage links, spreading it out evenly.
Cover the baking dish or roasting pan with aluminum foil.
Roast in the preheated oven for 25-30 minutes, or until the sausage is cooked through and the peppers are tender.
Remove the foil and return the dish to the oven. Roast for an additional 10-15 minutes, or until the sauce is bubbly and slightly thickened.
Remove from the oven and let it rest for a few minutes.
Garnish with fresh parsley or basil, if desired, before serving.