Rinse duck breasts with cold water, pat dry, cut the skin into diamonds.
Let the oil get hot in the pan, fry the duck breasts vigorously (first on the skin side) on each side for approx. 3 minutes and then season with salt and pepper.
Place the duck breasts skin side up in an ovenproof dish. Fry in a preheated oven at 200 degrees for approx. 40 minutes until crispy.
Peel the mangoes. Cut out the pulp from around the core, cut half of it into wedges and the rest into small cubes. Steam the mango cubes in the frying fat for approx. 5 minutes. Then add the coconut milk and stock, simmer a little, stir in the cranberries and green pepper. Season the sauce with salt and pepper.
Slice the duck breasts diagonally and serve with the sauce. Garnish with the remaining mango slices.