Veggie version (very cheap standby!):
Heat tablespoon olive oil in wok or big pan. Add: 3 chopped onions (2 if large!); 3 chopped peppers (4 if small!); 100g mushrooms, sliced; anything else to hand, eg. carrots, baby corn or courgettes.
Saute until veg is cooked but still retains a bit of 'bite', then pour in jar of pasta sauce. Add tin chopped tomatoes. Optional, any of the following: handful frozen peas; 1/2 pack frozen Quorn mince; tin kidney beans.
Leave that to simmer whilst you cook 400g pasta shapes as on packet (if anything undercook SLIGHTLY), & make cheese sauce - melt knob of butter, stir in flour to make paste (over heat), stir in 3/4 pint milk (using whisk prevents lumps), bring slowly to simmer, when thickened throw in handful grated cheese.
Mix veg glop & pasta, tip into casserole or any oven proof receptacle. Top with cheese sauce & more grated cheese mixed with breadcrumbs.
Bake in oven for 30 mins (GM 6) or till browned & bubbling.
Serve with salad &/or garlic bread - should feed 4-6