Salads of the actually satisfying variety are good; I like ones with mayonnaise. So, potato salad, or egg mayonnaise, for instance. I like the combination of pasta, hard-boiled egg, garlic and olives in mayonnaise (though my Patrick said it was better with some of the leftover Xmas ham added).

Or there's a really nice salad I sometimes make with rice and tuna and red and green peppers and chunks of garlic sausage and onion and garlic and french dressing (I don't even like peppers but I'll eat them in this!).

Patrick often takes left-over bolognese sauce or chili con carne to work for his lunch - those could be made in bulk beforehand. You could also do it with what I call "sausage stuff" - a tomato-based sauce like bolognese but with chopped-up sausages instead of mince and slightly different herbs.

Just a few thoughts...