Adjust rack to middle position (middle and top positions for 4 servings) and preheat oven to 450 degrees. Wash and dry produce.

Trim and slice scallions, separating whites from greens. Quarter lime.

In a medium bowl, combine coleslaw mix, scallion greens, ¼ tsp sugar (½ tsp for 4 servings), juice from half the lime, and a pinch of salt.

In a small bowl, combine Sriracha and mayonnaise. Add water 1 tsp at a time until mixture reaches a drizzling consistency.

Drizzle tortillas with 1 TBSP oil (2 TBSP for 4 servings); brush or rub to coat all over.

Arrange on a baking sheet in a single layer. Gently prick each tortilla in a few places with a fork. (For 4, divide between two baking sheets; toast on middle and top racks, flipping tortillas and swapping rack positions halfway through.)

Toast on middle rack, carefully flipping tortillas halfway through, until lightly golden, 4-5 minutes per side. TIP: Watch carefully to avoid burning.

While tortillas toast, heat a drizzle of oil in a large pan over medium-high heat. Add pork* and scallion whites. Cook, breaking up meat into pieces, until browned and cooked through, 4-6 minutes.

Stir in sesame seeds, chili sauce, hoisin, and ¼ cup water (½ cup for 4 servings). Cook, stirring constantly, until sauce has thickened, 1-2 minutes.

Divide tortillas between plates; evenly top with pork and slaw.

Drizzle tostadas with as much Sriracha mayo as you like. Serve with remaining lime wedges on the side.