I have been making this particular chicken dish forever. In fact, I may even have posted about it before - I'm too lazy to scroll back through nearly five years of posts to confirm or deny. It is always delicious, even though it's an old chestnut.
The secret is in the browning. The chicken pieces, the mushrooms and the onions all need to be well browned before you proceed, or you'll get a dish that looks as if it needs a transfusion.
I'm an impatient browner. That's a lowering confession from one who prides herself on her cooking skills, but it's the truth. Browning is boring. Because it takes so long to do it right, I usually start reading a book and end up almost blackening, which is nearly as bad as wimpy browning.
You, of course, will never have that problem. You will heat your skillet, drop in to sizzle the olive oil and butter, and brown the chicken beautifully, removing to a plate each piece to rest as it reaches golden perfection. Then you will brown your mushroom pieces (I like chunks) and your peeled pearl onions in that same lovely chickeny pan. When your mushrooms have a nice crust and the onions are dark in spots, you'll add back your chicken pieces and any juices that have collected, nestling them down amongst the vegetables, and you'll add your garlic chips stirring for a few seconds, your chopped tomatoes and a glug of white wine. You will add some herbs, too, either fresh or dried - if you're like me, Provençal herbs will be featured strongly, but bay leaf is a nice addition, too.
You will cover the pan and lower the flame to simmer for about 20 minutes, perhaps lifting the lid once or twice to baste the chicken with the pan juices and to fill your kitchen (and your entire house) with scents designed to bring your significant other in from another room and your dog to hover under your feet. Even cats become attentive and eager to please when this chicken is cooking. You may leave the lid off for the last several minutes to concentrate the sauce before plating.
Make it now, while there are still ripe tomatoes to be enjoyed. It may be a chestnut but it's a golden oldie.