Adjust rack to top position and preheat oven to 450 degrees. Wash and dry produce.

Slice potatoes into ¼-inch-thick rounds. Toss on a baking sheet with a large drizzle of oil, Fry Seasoning, salt, and pepper.

Roast on top rack until lightly browned and tender, 18-20 minutes.

Trim green beans if necessary. Swap in green beans for potatoes. Roast until green beans are until tender and browned, 10-12 minutes.

While potatoes roast, halve, peel, and dice onion. Halve buns.

In a small bowl, combine BBQ sauce, ketchup, chili powder, stock concentrate, half the cornstarch, and 1 TBSP water. (For 4 servings, use all the cornstarch and 2 TBSP water.) Set aside.

Heat a drizzle of oil in a large pan over medium-high heat. Add onion; cook, stirring, until softened, 4-5 minutes.

Add beef*; season with salt and pepper. Cook, breaking up meat into pieces, until browned, 3-5 minutes (it’ll finish cooking in the next step). 

Add BBQ sauce mixture to pan with beef. Cook, stirring, until sauce has thickened and beef is cooked through, 2-3 minutes. Taste and season with salt and pepper. Turn off heat.

While filling cooks, toast buns until golden brown.

Fill buns with as much beef filling and sliced pickle as you like. Divide sloppy joes between plates. Serve with potatoes and any remaining pickle on the side.