In a bowl, mix the garlic, rosemary, one and half cup of whole milk, about a quarter cup of olive oil, and salt and pepper to taste.
In a large oven baking dish, place the liquid and add the pieces one at a time making sure they are well soaked. Do it by hand.
Place about a kilogram of washed baby potatoes among the chicken pieces. Cut the potatoes in half if they seem too big.
Add half a cup of milk on top.
Place in a hot oven (200º C. / 390º F.) for 30 minutes. Turn the chicken pieces and mix the potatoes, and continue cooking for about 15 minutes. Turn the chicken pieces once more and leave for another 10 minutes making sure the chicken and the potatoes have a golden color.