Gently heat the olive oil in a large pot. Add the garlic, onion, chosen pepper and sauté until tender for about 3 to 4 minutes then add the mushrooms. Cook for a further 2 minutes.
Add the chicken sausage meat, combine and break the meat down with a spoon and cook together with the vegetables until no longer pink. About 5 minutes.
Stir in the chilli powder, oregano and then add the chopped tomatoes. Combine well together and bring everything to the boil.
Add the penne pasta, stir well together again. Reduce the heat to a gently simmer, cover the pot and cook for 15 minutes until the pasta is tender. Be sure to check and stir whilst the pasta is cooking.