Heat the olive oil in a large pot over medium heat. Add the sliced Italian sausage and cook until browned on both sides, about 5 minutes.
Add the sliced onion and bell peppers to the pot. Cook for 4 to 5 minutes until the vegetables start to soften.
Stir in the minced garlic and cook for 1 minute until fragrant.
Pour in the diced tomatoes with their juices and the chicken broth. Add the Italian seasoning along with salt and black pepper to taste.
Bring the mixture to a simmer, then reduce the heat to low. Cover and cook for 15 minutes to let the flavors combine.
Ladle the stew into bowls and top with chopped fresh parsley before serving.