Get some cooked or almost cooked vegetables (I used onion, peas, cauliflower, mushrooms, leeks and new potatoes and I sauted the onion, leeks and mushrooms in a little oil with some garlic puree first). Leftovers would be great.
Add shreds of meat or pulses if you want. I used some YS cooking bacon, but you don't have to, it can be all veg.
Add herbs and salt/pepper to taste.
Make a bechamel or cheese sauce - I made a bechamel sauce and steeped the warmed milk with a bay leaf and ground nutmeg before making the sauce. It is delicious but also it saves on the cheese. (Well, this is a frugal blog, isn't it?)
Put the vegetables, mixed up, in an ovenproof container. Pour over the sauce and let it 'soak' down. Top with grated cheese and bake in the oven until it is bubbling and the cheese is golden brown.
Serve on it's own or with a nice side salad or some garlic bread.
Loads of variations are possible with this one. I love it! A meal in itself and utterly delicious (if you love cheese!).