It was either Kotopoulo Kokkinisto or Kotopoulo Stifado. Kokkinisto is made just with a little onion, some white wine, and tomatoes more or less. It's a very simple dish.
Stifado is a bit more involved but still simple. It's kind of a greek version of coq au vin and onions play a starring role. Dark meat works best here. You need lots and lots of onions, some garlic, some tomato paste, a few crushed tomatoes (not too much or omit altogether), red wine, a pinch of cinammon, a couple of cloves, and bay leaf. Basically you season and dust the chicken in flour and brown it on each side in a little olive oil in a dutch oven. Remove from the pot and then sautee the mountain of onions and garlic and then add some tomato paste to toast along. Deglaze with red wine, you probably don't need more than 2 cups. Add the remaining ingredients and bring to a simmer. Then put the chicken back in and leave it to braise on the stove top for about about 90min. Onions of choice for me are shallots, which will eventually disintegrate in the sauce. You can also use pearl onions which look pretty later. Traditionally served with rice or crusty bread to mop up the delicious sauce.
This exact recipe can also be used for rabbit, with the addition of a little vinegar. Geez it's been ages since I made stifado. If I haven't helped you find the recipe you're looking for at the very least you've helped me find a dish for my dinner menu some time this week.