- Make the tamales: In a food processor, puree corn kernels with 4 cups water. Add Maseca, sugar, baking powder, salt, lard, and melted butter. Blend until ingredients are thoroughly mixed, then chill the batter in the refrigerator for 30 minutes.
- Working in batches, remove husks from water and pat dry. Spread a few tablespoons of dough in an even layer across the wide end of two husks layered on top of each other, leaving a ½-inch border around edges. Wrap the husk. Then, with the seam up, fold up the narrow tail of the tamale. Repeat until you fill 25 tamales. Place the tamales in a steamer. Close the lid tightly and steam for 60 minutes, checking every 15 minutes to make sure the water hasn’t evaporated.
- Make the salsa: Heat a dry, large skillet over high heat. Add peppers to form a single layer in the pan. Cook, tossing occasionally, until blistered in areas but still green, about 4 to 6 minutes. Do not let them collapse or soften. Reserving a few whole peppers for garnish, coarsely chop the rest and place in a small bowl. Mix in garlic, vinegar, and oil. Season with salt and pepper.
- Make the crema: In a 12-inch pan over medium heat, saut. butter, shallots, and garlic until ingredients are soft and translucent. Add cream and reduce by half. Stir in crabmeat and roe, and heat until warmed through. Taste and adjust seasoning with salt and pepper. Finish with a squeeze of lemon.
- To assemble: Arrange tamales on a platter. Generously drizzle with crema first, then salsa. Garnish with reserved shishito peppers.