While you boil the water for the pasta, add oil to large pan (large enough that you can add the pasta to the pan after). Cook the sausages until no longer pink. Remove sausages and add onion and garlic. Cook until soft. Add peppers and cook until tender-crisp. Return sausages to pan, add chicken broth, parsley, hot pepper flakes and salt & pepper to taste (I usually add the salt and pepper while I'm cooking sausages - as well as an extra couple dashes of garlic powder). Let this simmer for about 5-10 minutes while pasta is cooking, then add drained pasta to pan and toss. Sprinkle each serving with parmesan cheese.