Make the sauce—in a bowl, stir together the ketchup, relish, chiles, and sour cream; season with salt and pepper.
Make the burgers—in a large bowl, combine the beef, chili powder, coriander, cumin, and Worcestershire sauce; season with salt and pepper and mix thoroughly.
Score the mixture in to 4 equal portions and form 2 thin patties out of each section, creating 8 patties total.
Heat a drizzle of oil in a large skillet or griddle over med-high heat.
Cook half the burgers until browned and cooked through, about 2 minutes on each side.
When you flip the burgers, top each with a slice of cheese.
Set the first batch aside on a plate and cook the remaining burgers.
When the burgers are ready, assemble them in a double-decker style—lay down 4 bun bottoms and top them with some of the sauce, a lettuce leaf, a burger, a couple of pickle slices, and a sprinkle of onion.
Repeat with another layer (using 2 bun bottoms and 2 bun tops) of the same order.
Add some of the sauce to the top buns, too, before you cap off each burger.