Heat the oven to 190C/fan 170C/gas 5. Find a roasting tin or baking dish in which the chicken will fit in a single layer but with a little room around each thigh. Put the onion wedges in the bottom, add 1 tbsp olive oil, toss and spread evenly. Sit the chicken on top and season the skins. Cook in the oven for 30 minutes then remove and lift out the chicken. Add the remaining ingredients, season and mix well. Sit the chicken thighs back on top then return to the oven for 20-25 minutes or until the chicken is crisp and golden, and the sauce reduced. Serve with rice, couscous, short pasta or some greens and crusty bread, if you like.