Start by mixing the buttermilk with paprika, garlic powder, onion powder, salt, and pepper in a bowl. Add the shrimp and let them soak for 15 minutes—this brining process seasons the shrimp throughout and keeps them tender. While the shrimp marinates, prepare the bang bang sauce by whisking together the mayonnaise, chili sauce, sriracha, soy sauce, and lime juice in a separate bowl. I like to taste the sauce at this point and adjust the heat or sweetness to my preference—it should be creamy, slightly spicy, and balanced.
While the shrimp finishes marinating, thinly shred the cabbage into 1/8-inch strips and place it in a bowl. Toss the cabbage with lime juice, avocado oil, lime zest, salt, pepper, cilantro, and honey. The honey adds a subtle sweetness that complements the tang of the lime and balances the spicy sauce beautifully. Set the slaw aside—it will soften slightly and develop better flavor as it sits.
Remove the shrimp from the marinade, letting excess buttermilk drip off, then coat them evenly with cornstarch—this creates an incredibly light and crispy exterior. Heat the avocado oil in a large skillet over medium-high heat until it shimmers. Working in batches if needed to avoid overcrowding, fry the shrimp for 2-3 minutes per side until they're golden and crispy, with the cornstarch coating turning a light golden brown. Transfer the cooked shrimp to a plate lined with paper towels.
Place the fried shrimp in a bowl and pour half of the bang bang sauce over them, tossing gently to coat evenly—reserve the remaining sauce for serving. While the shrimp finishes coating, briefly char the corn tortillas over a gas flame or in a dry skillet to enhance their flavor and make them pliable for filling. This charring step adds a subtle smokiness that elevates the entire taco.
Lay out a charred tortilla and fill it with a generous portion of the cabbage slaw from Step 2, then top with 3-4 pieces of the bang bang shrimp. Drizzle with the reserved sauce, then garnish with sliced green onions, fresh cilantro, and a squeeze of lime juice if desired. The cool, crisp slaw provides the perfect contrast to the hot, creamy shrimp and spicy sauce.