In a bowl add all of the ingredients for the masa with rice. Stir well to combine and taste for salt. Keep covered with plastic wrap so it does not dry out.
Cut banana leaves to desired size. Preheat a comal(griddle) to medium heat for 4-5 minutes. Lay the pieces of banana leaves on the hot comal. You will see them begin to change color, soften and become shiny. Turn as needed and set aside. The leaves must be heated this way before assembling tamales.
Peel and clean the shrimp. Preheat 5 cups of salted water to medium heat. When it comes to a boil, gently add the shrimp and poach for 2-3 minutes or just until it turns pink. Immediately transfer to a bowl of ice water. Reserve until ready to use.
For salsa cruda, combine all of the ingredients to the blender. Pulse to blend until desired smoothness. Taste for salt ans set aside.
Drain the poached shrimp and slice open, then apart to yield two thin sliced pieces of shrimp.
Assembling Tamal: Take 2 of the leaves and stack them on top of each other. To the center, add about 1/3-1/2 cup of the masa with rice. Add 3 sliced shrimp, 1 jalapeño strip and 1 tablespoon of salsa cruda. Fold in the sides until they overlap. Then fold in the top and bottom. Tear off a few strips of the extra banana leaf and tie each end.
To Cook: Fill the bottom of a pot with 4 cups of water. Insert a metal steamer. Arrange tamales laying down and layered. Cover with lid and turn heat to high. When it begins to steam rapidly, reduce heat to medium. Set your timer for 45 minutes. After 45 minutes, add 1 cup of hot water to the bottom of pot, pouring in carefully to one side of the pot. Cover and continue steaming for another 45 minutes. Remove from heat and let sit for 20 minutes.