Heat the oil in a heavy large skillet over medium heat. Add the sausages and cook until brown on both sides, about 7 to 10 minutes. Remove from the pan and drain.
Keeping the pan over medium heat, Add the Italian seasoning, basil, and garlic and cook 2 more minutes.
Add the Marsala wine, tomatoes, tomato paste and stir, add chili flakes, if using.
Add the peppers, onions, salt, and pepper and bring to a simmer.
Return sausage to skillet with the vegetables. Reduce heat to low, and simmer 15 minutes, or until the sauce has thickened.
Serve over mashed potatoes, noodles, polenta, cauliflower rice or, if serving as a sandwich, split the hoagie rolls in half lengthwise. Hollow out the bread from the bottom side of each roll, being careful not to puncture the crust. Fill the bottom half of the roll with sausage mixture.