As an L.A. native, Alvin Cailan has a soft spot for the classic West Coast-style burger: thin patties, simple bun, and Thousand Island dressing.

The one he's teaching us to make today comes from California's cult fast-food chain. It's a burger that spawned a whole movement of secret-menu items and cemented the West Coast's burger legacy.

Alvin says by simply glazing mustard on the patties while they cook, it creates caramelization that gives the burger deep flavors. But the true secret ingredient is chopped chiles, a small addition that provides an important tang to cut through the richness. Safe to say—it's an instant classic.