Cook pasta until al dente. Meanwhile empty a tin of chopped tomatoes into a saucepan, add a crushed clove of garlic, salt & black pepper. Bring to a gentle simmer, add some grated parmesan and mozzarella and let it melt. Put drained pasta into ovenproof dish, pour over sauce and sprinkle on some more parmesan. Pop in a hot oven or under a grill until cheese melts and bubbles. Serve with crusty bread.
Another one:
Cook pasta. In a saucepan add sliced mushrooms to a jar of Dolmio tomato sauce (the spicy one's nice). When mushrooms cooked through add to drained pasta and serve sprinkled with parmesan (15 min max from start to finish). Serve with garlic bread.
Another one:
Cook spaghetti or linguine. Drain. Add 2 dessertsps of green or red pesto sauce per person and stir in with some toasted pinenuts. Serve with a beef tomato and onion salad.
All of the above can be adapted to include things like chicken or tuna.