Thick grilled cheeseburger with onions and serrano pressed into the patty

Form the ground beef gently into a patty on a plate or tray, a little bigger than the bun since it shrinks.

Season one side with salt, pepper and MSG and the other with Cajun Sparkle.

Slice the onion thin and press it into the outside of the patty rather than mixing it in, which gives a meatloaf flavor and raw or steamed onion; press serrano slices in under it.

Set out oil in a bowl and a paper towel for the grates, the spatula and the condiments.

Preheat the grill about 15 minutes with one side low and one hot; oil the grates in a couple of coats, letting the first smoke and polymerize.

Grill chili side down over the hottest part with the lid closed (higher heat on a gas grill) and sear a couple of minutes.

Flip, pushing back any onions and chilies; hold the spatula over the hottest part to sterilize it from raw meat juices.

Cook the second side a few minutes until really nicely crusty and browned.

Add the cheese and toast the bun on the grill.

Build from the bottom: jardiniera mayo, pickles, tomato, then lettuce right under the burger as an anchor that absorbs the juices.