Bring a pot of water to a boil for the pasta.
Roast peppers over flame on stovetop or under broiler to blacken the skins all over. Place peppers in bowl and cover with plastic wrap until cool. Peel skins and seed peppers.
Place roasted red peppers and chili peppers in a food processor and add the nuts, basil, oregano, garlic, salt and pepper. Add cheese, turn processor on and stream in the EVOO to form a thick sauce.
Salt pasta water and cook spaghetti to al dente. Reserve about 1 cup of starchy cooking water, drain pasta and return to pot. Toss pasta with pesto and half the starchy water. Toss the pasta with the sauce for a minute or two to combine thoroughly, adding a little more starchy water if necessary. Serve with more cheese and some torn basil leaves or finely chopped mint and parsley, if desired.