Wash and dry all produce. Thinly slice jalapeño into rounds, removing ribs and seeds for less heat. Zest and halve lime. Trim and thinly slice scallions. Roughly chop cilantro.

In a small bowl, combine juice from half the lime, 1/2 tsp sugar (1 tsp for 4 servings), 1 TBSP water (2 TBSP for 4), and a large pinch of salt. Add jalapeño; stir to coat. Set aside to pickle, stirring occasionally, until ready to serve.

In a medium bowl, whisk together sour cream, half the lime zest, 1 tsp Southwest Spice (2 tsp for 4 servings), 1/2 tsp sugar (1 tsp for 4), and a squeeze of lime juice to taste. Season with salt and pepper. Add coleslaw mix, scallions, and cilantro; toss to combine. Season again with salt and pepper. Set aside.

Rinse shrimp under cold water; pat very dry with paper towels. Season with salt. In a large bowl, combine tempura mix, remaining Southwest Spice, salt (we used 1/2 tsp; 1 tsp for 4 servings), and 1/3 cup cold water (2/3 cup for 4) until smooth. (TIP: If mixture is too thick, add more water 1 TBSP at a time until it reaches a pancake-batter-like consistency.) Heat a 1/4-inch layer of oil in a large, heavybottomed pan over medium-high heat. Stir shrimp into batter until fully coated. Line a plate with paper towels.

Once oil is hot enough that a drop of batter sizzles when added to the pan, add coated shrimp in a single layer. (You may need to work in batches.) Cook until golden brown and cooked through, 2-3 minutes on the first side and 1-2 minutes on the second side. Using a slotted spoon, transfer shrimp to paper-towellined plate. Sprinkle with remaining lime zest, salt, and pepper.

Wrap tortillas in damp paper towels and microwave until warm and pliable, 30 seconds. Fill tortillas with shrimp, as much slaw as you like (serve any remaining slaw on the side), and pickled jalapeño to taste. Serve.