Cook spaghetti as per package directions. Drain and set aside.
Heat oil in a skillet. Add chopped onions and garlic. Sauté until golden, then add the chopped oyster mushrooms. Add wine and sauté until the mushrooms are tender.
Add chopped peeled tomatoes, basil, chili powder, salt and pepper. Cook for another 2-3 minutes.
When ready pour over the spaghetti and mix gently.