Preheat oven 350F. Fry onion and garlic for 4 minutes in 2 teaspoon olive oil. Add mushrooms, cover and cook 5minutes. Stir in apple. Add tomatoes and 1 teaspoon sage and 2 tablespoon tomato puree. Cover and simmer gently for 10 minutes or til sauce is fairly thick. Meanwhile cooke spaghetti 5-7 minutes til just tender. Drain and add to sauce. Turn mix out into a casserole dish. Sprinkle grated cheese on top and bake for about 25 minutes.