Lentil dahl, rice and naan - make a big quantity of the dahl and freeze here Chicken and leeks pie with mashb top - i use left over roast chicken and leeks or mushrooms. I use this sauce Oven baked risotto here i use this method but vary the vegetables and sometimes use left over roast chicken
One more idea, make a huge pot of tomato sauce - tinned tomato, lots of vegetables, garlic, some herbs and cook in the oven for ages so it goes really thick and the vegetables disappear (helpful when toddlers are around). Then use this with pasta, stirred into rice, as a base for other sauces e.g bolognase, on muffins with cheese and grilled to make mini pizza, with fish etc. Freeze in portions for a quick lunch.