Prepare the Patties: In a large bowl, mix the ground beef (or chosen protein) with salt and pepper. Form the mixture into 4 equal-sized patties, making a slight indentation in the center to prevent them from puffing up during cooking.
Grill the Patties: Preheat your grill to medium-high heat. Grill the patties for about 4-5 minutes per side, or until they reach an internal temperature of 160°F for beef (165°F for chicken or turkey). Brush BBQ sauce over the patties during the last minute of grilling, allowing the sauce to caramelize slightly.
Toast the Buns: While the burgers are grilling, lightly toast the buns on the grill for 1-2 minutes, until golden brown.
Assemble the BBQ Burgers: Place a slice of cheese on each patty during the last minute of grilling to melt (optional). Spread a layer of BBQ sauce on the bottom half of each toasted bun. Add the patty, then top with crispy fried onions and pickles (if using). Finish with the top half of the bun.