This is a basic version of a recipe -- which is not very complicated in the first place -- in Simon Hopkinson's Roast Chicken and Other Stories. It serves three: an awkward number. A single can of tomatoes does not produce a generous quantity of sauce for four: so you might, if you have that number to feed, add an extra third of a can, plus some more vinegar.
1 dstsp olive oil
6 chicken thighs
2 cloves garlic, chopped
150 ml red wine vinegar
400 g can tomatoes
Handful parsley, chopped
Warm the olive oil in a heavy pan large enough to contain the chicken in a single layer. Salt the thighs, place them skin-side down in the pan, and brown them over a moderate heat for 10 to 15 minutes, turning once. You should need only this small amount of oil, because the chicken pieces will exude their own fat.
Throw in the chopped garlic, allow it to soften in the oil, and pour in the vinegar. (You could add rosemary and bay at this point.) Simmer gently for 10 to 15 minutes, until well reduced. Add the tomatoes, breaking them up with a wooden spoon (it becomes easier once they have cooked for a while), and simmer, uncovered, until the sauce thickens -- about 30 to 45 minutes. The oil will separate from the tomatoes: you can discard some of it if you like. (I do not.) If the sauce is still liquid as you approach meal time, remove the chicken to a warm plate, turn up the heat and bubble the sauce to reduce it. Return the chicken to the pan to warm through.
Check the seasoning. Stir in the parsley. It needs pepper, in my opinion; you might add it at the table.