Cut duck in pieces. In a bowl combine salt, pepper, ground cumin, 1 tablespoon garlic, aji limo, half of fresh yellow aji, and half sundried yellow aji. Place duck pieces inside and mix together to coat. Marinate for 30 minutes. Remove duck pieces and reserve marinade.
Heat 2 tablespoons oil in a skillet or a medium saucepan and sear duck until golden. Set aside.
Heat 1 tablespoon oil in another saucepan and sauté diced onion, remaining garlic, sundried yellow aji and fresh yellow aji. Cook until soft, add duck pieces and the reserved marinade. Season with salt and bring to a boil for 30 minutes. Add the onion cut into thick julienne and cook 15 minutes more.
Serve Duck ceviche with cooked yucca or cassava, garnish with lettuce leaves and chopped red aji.