The main secret is to cook it for a very long time on a very low eat.
I use onion, garlic, tin of tomatoes, dried herbs, salt and pepper, squirt of tomato puree, chicken or beef stock. Sometimes a splash or wine or worcester sauce, or even a spoon or marmite in a beef casserole. The meat and veg of course. If you brown off the meat and some of the veg in a pan first, that intensifies the flavour too. Then bung it in the oven with a lid on at about 160-170, for 2 or 3 hours.
Tinned prunes are nice with beef, they sort of disintegrate into the sauce (don't do what dh did and leave the stones in though). for chicken I use onions, carrots, garlic and rosemary, a tablespoon of cornflour mixed with a bit of water and a splash of tamari soy sauce.
I use similar to celery and it is always delish. A bay leaf ot two added also helps. I also use the kallo organic stocks as I think they have a nicer taste than say oxo. If making a chicken casserole I usually use a mix of thigh and breast meat and roll it in seasoned flour then brown it. The flour helps to thicken the sauce. My fail-safe chicken casserole recipe is just onion, garlic, red and green peppers, celery if I have it, mushrooms. Saute in olive oil. Add tin toms and about 300ml of chicken stock. Chuck in bay leaf, maybe oregano, salt and pepper (lots). Or paprika is nice. Prepare chicken as above and bung in a large lidded casserole. Stick in oven for a couple of hours. Serve with rice, pasta, or couscous. I guess this is quite a meditteranean sort of flavour, not like a coq au vin type of thing. The veggie/sauce bit can also be saved and makes a great lunch the next day with crusty bread, sort of a thick soup.
Always cook on low heat as have aga and can leave all day ( almost like slow cooker)- so easy whioch is why we live on casaroles during winter
Mrs Jamin - would you add water to stock cube or dissolve inred wine? Proyaffle - am confused re chicken - if just cornflower and bit of water is it enough for the chick and veg to cook in? - sorry if being a bit "slow"
Mrsmalunbas - ahaa....coat meat in flour - this would solve the atery problem I am left with....
I have defrosted chickne for tonight in anticipation- will digest responses more thoroughly and post to tell you how I am going ot coook.....