Instructions:
- Prepare the Secret Sauce: In a small bowl, vigorously whisk together all sauce ingredients until fully emulsified and smooth. Cover and refrigerate for at least 15 minutes to allow flavours to meld.
- Form the Patties: Gently combine the ground beef, salt, pepper, and Worcestershire sauce in a bowl. Do not overmix. Divide into four equal portions and gently shape into patties slightly wider than your buns, creating a small dimple in the centre of each.
- Toast the Buns: Melt the butter in your skillet over medium heat. Place the buns cut-side down and toast until golden brown (about 1-2 minutes). Remove and set aside.
- Cook the Burgers: Wipe out the pan and set the heat to medium-high. Place patties in the hot pan. Cook undisturbed for 3-4 minutes until a deep brown crust forms.
- Flip and Melt: Flip the patties. Immediately top each with a slice of cheese. Cook for another 3-4 minutes until the cheese is fully melted and the burgers reach desired doneness.
- Final Assembly: Place a layer of lettuce on the bottom bun. Top with the cheesy patty. Liberally slather the top bun with the prepared Secret Sauce. Add optional sautéed onions, cap the burger, and serve immediately.