As is the case with chickens, you should cook the breasts for only 30 minutes or so, to keep them tender.
1 guinea fowl, in four pieces
Knob of butter, tbsp of sunflower oil
450g shallots, peeled
4 cloves garlic - 2 chopped, 2 left whole
80g smoked pancetta, cubed
50ml balsamic vinegar
80ml chicken stock
Warm the butter and oil in a heavy casserole, and gently fry the guinea fowl pieces, salted. You may need to do this in two batches of two. Keep the heat low; you don't want the fat to burn. When browned, transfer to a plate.
Throw in the shallots, garlic, and pancetta. Cook for a minute or so to allow the garlic to soften. Pour in the vinegar, and let it bubble and reduce for a minute. Pour in the stock. Return the guinea fowl legs, but not the breasts, to the casserole, cover, and transfer to an oven. (I might have added some bay, or perhaps thyme or rosemary.)
The oven setting will depend on the heaviness of your casserole. The Le Creuset pictured above will simmer stews quite gently on gas mark 4/180C, whereas my smaller, round Le Creuset, once heated up, will perform efficiently at gas mark S/130C.
I like to cook forgiving cuts of meat until the meat is falling off the bone. I gave the legs 90 minutes before adding the breasts, and giving them another 30 minutes.
There was plenty of sauce. But stews can dry out in certain dishes or atmospheric conditions. Add more stock or water if necessary.