God, I think lasagne is a huge hassle tbh, though not complicated per se it takes forever and hundreds of pans (OK, 3).
TBH roast chicken with roast veg is the easiest meal I know.
2 hours before eating, preheat oven to temperature on chicken packet. Unwrap chicken and put in large baking tray. Put bacon slices over chicken if liked. Put foil over chicken and put in onion for 1 hour. Peel and half some potatoes, cut some carrots into 3 chunks each, peel some onions and cut in half, take some garlic cloves out of their white stuff (but leave inner pink stuff on).
Take out chicken, take off foil. Surround chicken with veg, and also sausages if liked. Replace foil and put tray back in oven for 30 mins.
In last 15 mins, bring some water to the boil, put colander on top with lid on top of that. Put broccoli florets into water and leeks into colander. Boil water for approx 7 mins or until veg are tender.
Put chicken onto carving tray (or chopping board and get someone else to handle all veg while you make gravy.
Take roasting tray with all juices in it and put on hob. Heat fiercely. Put dessertspoonful of plain flour in and use metal spoon to stir it in, reducing lumps as much as possible and scraping up all the bits on the tray. Cook, still stirring, for a couple of minutes. Add enormous splash of fruit juice (lemon is nice with chicken, or apple, whatever you have) so that you have enough volume of gravy. Stir and cook for another minute or two. Pour into jug (via a strainer if necessary).