you can use whatever part of the chicken although legs will be less prone to dry. but this is all up to your ability in front of the fires.

then it's tomatoes (I like san marzano, but also ripe cherry tomatoes as in your dish is fine I think) and tomato sauce (try to find some that has the right amount of "water" in it, saying not too much tomato pulp).

then olives, capers (it's a harsh debate between in vinegar - salamoia- or salted; il leave it to you. if you choose salted, they're gonna be really salted, keep this in mind), fresh basil, spicy peppers, oregano. and my personal taste is garlic. all of this with the best olive oil you can find. obv, salt.

so you peel and just break a little the garlic and let it go in a pan with more warm than hot oil, just to release garlic's first odor. then it's literally all of the other ingredients together. you may want to heat a bit the tomato sauce and slightly cut the ripe tomatoes before adding the rest. thermal shock it's important. be wary for the sauce not being, as i said, too watery or too dry, because that's what going to cook the chicken and soak it. you're going, after the very first minute or two, to low the fires, cover the pan and let it go, slowly. this is going to take the time it takes, depending on the water in tomato sauce, and general equilibrio of cooking of chicken and tomato sauce so to say. if it's too dry, adding water may limit your access to italian soil for a few years. just don't tell anyone, if you do it. not even your spouse. result is not guaranteed, this way.

for the quantities, I'm sorry but it's all in the eye, I cannot be precise. there should be oil in that pan, abundant so to say. tomato sauce should be enough to cover the bottom of the pan and a small part of the chicken. don't overdo with basil, oregano and capers. I like basil after the cooking, when the pan cools down, covered. taste it before adding salt, you may prefer small grained salt to fix it eventually; anyway wait for the capwrs to release their salt before adding more salt. stir it gently and often, use a spoon to bring sauce on chicken, you know the usual things.

as a plus you may cut slices from a loaf of bread, and use it to consume the tomato sauce.

lastly this is one of the very many recipes you'll found about this dish if you talk to italian people. it's my favorite one though.

very last, red wine or a solid stout, if you drink alcohol. water is absolutely fine with it.

ps. feel free to ask, it's late and I'm sleepy. could have missed, misspelled, etc. thank you