Tray bakes are so simple.
Chicken thighs with skin on, quartered red onions, peeled carrots in chunks, baby new potatoes, Toss them all in a splash of olive oil and garlic paste with a heap of fresh chopped thyme or rosemary, sprinkle with sea salt and black pepper. Pour a glass of white wine over it and roast in oven for 40 mins.
Or chicken pieces with chunks of mixed peppers, baby tomatoes, olives and aubergine, tossed in garlic and mediterranean herbs, served with crusty bread and salad
Or chorizo and butternut squash with red onions, chickpeas and red peppers, tossed in oil with cumin seeds or powder, smoky paprika, garlic and lemon zest.
Or good Cumberland sausages with thickly sliced sweet or white potatoes, maybe some sliced fennel if people like it, and some fresh thyme, with a splash of cider. Serve with petit pois which just need bringing to the boil then turn off the heat.
Industrial quantities of slow cooked spag bol or chilli made in advance will transport well.