Actually dahl can be slimming. Just use a tiny bit of oil to start iff the onions, and then spices and chilli for lots of flavour. Not very many calories in that!
Use them with lots of veg in soups and casseroles.
Use them cooked in homemade bread.
Simply mashed with garlic paste in place of mashed potato.
Comine with curry spices and loads of veg and top with sweet potato or swede/ celeriac mash for lentil pie.
Cook with brown rice and spices.