Chicago-style Italian Sausage Subs

"Par-boil your sausages until cooked throughout. Finish them off on a grill or saute in a pan for another 5-10 minutes. Set aside and cover to keep warm.Place oil in a saute pan and grill onions until soft and tender. Add the red pepper, garlic and spices and saute for another 2 to 3 minutes. Add the diced tomatoes & simmer on low for 10 minutes to marinate flavors.Lightly broil hoagie buns, just until slightly toasted. Remove from oven.Add Italian sausage, then some of tomato mixture to each hoagie roll. Sprinkle mozzarella over each sub sandwich & then broil for another 1-2 minutes, or just long enough to melt the cheese.Enjoy !"