First, you need the right bread. A regular burger bun is a traitor to this cause. You need a sesame seed bun that’s soft, squishy, and tall. It’s the architecture of the thing that matters.
Now, here’s the secret: you need three layers of bun. The top, the middle, and the bottom. Yes, you are about to commit culinary bigamy by using an extra bun half. Don’t apologize to the bread.
Toast those suckers. Just a light golden brown in a dry skillet or under the broiler. Do not skip this step. Soggy buns are the enemy of happiness.