Wash and dry all produce. Split buns in half and set aside. Thinly slice cucumber on a diagonal. Trim and thinly slice scallions. In a medium bowl, combine scallions, cucumber, cabbage, vinegar, 1 tsp sugar (2 tsp for 4 servings), and a large drizzle of olive oil. Season with salt and pepper.

Melt 1 TBSP butter in a large pan over medium-high heat (use a nonstick pan if you have one). Add buns cut sides down and toast until golden, 2-3 minutes. Set aside. (For 4 servings, toast in batches.)

While buns toast, in a shallow dish, combine panko, 1/2 tsp salt, and half the Fry Seasoning (save the rest for step 5). Pat tilapia dry with paper towels. Brush 2 TBSP sour cream (1 packet—use 2 packets for 4 servings) onto fish, coating all over. Season with salt and pepper. Dip each fillet into panko mixture, coating all over and pressing to adhere.

Heat a 1/4-inch layer of oil in pan used for buns over medium-high heat. Once oil is hot enough that a pinch of breadcrumbs sizzles when added to the pan, add tilapia and cook until panko is golden and fish is cooked through, 3-4 minutes per side. (For 4 servings, cook fish in batches.)

In a small bowl, combine remaining sour cream, remaining Fry Seasoning, and half the hot sauce. Season with salt and pepper.

Cut tilapia into 3-inch pieces. Spread sauce on cut sides of buns. Fill buns with tilapia and a little bit of slaw. Drizzle with remaining hot sauce (to taste). Divide between plates and serve with slaw on the side.