Saute the chicken pieces in olive oil in the pot until they are golden brown. Add the duck breast and saute another few minutes. Remove and reserve on a plate.
Brown the onions and garlic in the chicken drippings. Remove from the heat and reserve.
Fry the bacon in another pan. *Cooks note: don't use any oil as there is enough fat in the bacon. When the bacon is crisp and the fat is rendered, combine with chicken and duck breast and set aside.
Mix the peeled tomatoes with the tomato concentrate and puree. Heat them in another casserole until they turn slightly golden. Add 1 1/2 tablespoons of the flour to thicken. Add the onions and garlic to the tomato mixture. Add the chicken, bacon, and duck and cover with 2 1/4 cups of water. Add salt and freshly ground black pepper. Bring to a slow simmer and cook for 40 minutes. Add 3 slices of blanched orange to casserole and leave for 15 minutes to allow the orange aromas to permeate the chicken. Then remove them and reserve for garnish.
To blanch the oranges, boil 2 cups of boiling water in a small saucepan. Add oranges and boil for 1 minute. Remove and leave to cool. Blanching the orange removes the bitterness.