Preheat a grill or broiler. Combine the chilies, pumpkin seeds, garlic, shallots and chicken stock in a blender. Puree for about 30 seconds. Transfer the puree to a saucepan. Bring to a boil. Set aside. Lightly brush the snapper fillets with the olive oil. Sprinkle with salt and pepper. Grill or broil the fillets 3 to 4 minutes on each side or until fish flakes easily. Just before serving, add the cream, basil, lime zest, juice and salt and pepper to the sauce. Simmer 3 to 4 minutes. Spoon the sauce onto the dinner plates. Top with the fish.