Step 1

Process dried shrimp in a blender until finely ground, about 10 seconds; leave in blender. Cook guajillo chiles, chiles de árbol, garlic, and whole serrano chiles in a large skillet over medium, turning often, until dried chiles are toasted in spots, 3 to 4 minutes. Reduce heat to medium-low, and carefully add clam juice, oregano, and 1/2 teaspoon salt. Cover skillet, and cook until dried chiles are softened, about 10 minutes. Transfer chile mixture to blender with dried shrimp. Secure lid on blender, and remove center piece to allow steam to escape. Place a clean towel over opening. Process until smooth, about 30 seconds. Reserve 1/2 cup chile puree for dipping sauce. Combine masa preparada and remaining chile puree (about 1 cup) in a large bowl; stir until well incorporated. Cover with a damp towel; set aside.

Step 2

Heat oil in a large skillet over medium. Add raw shrimp. Sprinkle with pepper and remaining 1 teaspoon salt. Cook, stirring occasionally, until mostly opaque and almost cooked through, about 2 minutes. Transfer shrimp to a medium bowl.

Step 3

Place 1 corn husk on a clean work surface with the narrow end pointing away from you; pat dry. Tear 2 (3/4-inch-wide) strips from sides of husk; set aside. Using a 13/4-inch ice cream scoop, add 2 tablespoons of chile masa to center of husk. Press 1 shrimp into center of masa ball. Fold one side of husk over so the masa encases the shrimp, and roll to wrap remaining husk around tamal. Tie 1 husk strip on each end of the tamal, pulling tightly and squeezing toward the center to form into an egg shape. Repeat with remaining husks, chile masa, and shrimp.

Step 4

Fill a large stockpot with 1 inch of water. Place a steamer insert (at least 7 inches deep) in stockpot, ensuring water does not touch bottom of steamer. Line bottom and sides of steamer with husks. Stack tamales horizontally in steamer, tucking in tightly.

Step 5

Heat pot over medium-high until steam is visible, 5 to 8 minutes. Place a layer of corn husks on top of tamales. Cover tamales with a clean kitchen towel, and place lid on top. Reduce heat to low. Cook 25 to 30 minutes. To test doneness, carefully uncover pot, and remove 1 tamal. Cover pot, and allow remaining tamales to keep cooking. Let tamal rest 10 minutes before unfolding. If masa sticks to corn husk, rewrap tamal, and return to steamer basket. Continue cooking tamales 5 minutes before checking again for doneness. If corn husk pulls away cleanly from masa, turn off heat, and let tamales rest in pot, lid removed, towel and husks still in place, for 15 minutes.

Step 6

While tamales rest, stir together Mexican crema, lime juice, and reserved 1/2 cup chile puree. Season to taste with salt. Serve tamales hot with chile dipping sauce; garnish with sliced serranos.