Step 1: Heat olive oil in a large skillet or Dutch oven over medium-high heat. Add the Italian sausage links and brown them on all sides for about 8-10 minutes. This step is crucial for developing a flavorful crust. Remove the browned sausage from the pan and set aside.
Step 2: In the same pan, reduce the heat to medium. Add the sliced onions and cook, stirring occasionally, until they are softened and translucent, which should take about 5-7 minutes. Scrape up any browned bits from the bottom of the pan to incorporate their flavor.
Step 3: Add the sliced bell peppers and minced garlic to the pan. Sauté for another 7-10 minutes, stirring frequently, until the peppers begin to soften and the garlic becomes fragrant. Be careful not to burn the garlic.
Step 4: Pour in the crushed tomatoes and chicken broth. Stir well to combine all ingredients, then bring the mixture to a gentle simmer. Incorporate the dried oregano, dried basil, and red pepper flakes (if using). Season generously with salt and freshly ground black pepper to taste.
Step 5: Return the browned sausage links to the pan, nestling them into the pepper and onion mixture. Cover the pan, reduce the heat to low, and let it simmer for at least 25-30 minutes. For a deeper flavor, you can simmer for up to an hour, allowing the flavors to meld beautifully.
Step 6: Uncover the pan and continue to simmer for an additional 10-15 minutes, allowing the sauce to thicken slightly to your desired consistency. Taste the sauce and adjust seasonings as needed. If the sauce is too thick, add a splash more broth; if too thin, continue to simmer uncovered.
Step 7: Garnish the finished sausage and peppers recipe with fresh chopped parsley just before serving. Serve hot and enjoy this comforting, hearty dish.