In a blender, combine the garlic, achiote paste and fish stock, puree to a smooth paste and reserve.
Green Grape Escabeche
In a glass bowl, combine the onion, jalapeño, grapes, lime juice and oregano, mix well. Season with salt and pepper and set aside.
Preheat the oven to 350º F.
Clean the banana leaves with a damp towel. Place each fish fillet on a banana leaf and brush each side with the achiote marinade. Wrap the banana leaf around the fillet and place on a baking-safe sauté pan. Once all the fillets are wrapped and in the pan, add the fish stock to the pan.
Bake the fish for approximately 15 minutes or until firm. Remove fish from the oven, and cut a slit off the top of the banana leaf to expose the fish. Top each fillet with the green grape escabeche and garnish with cilantro and a lime wedge.