"H-Bomb" burger.

This is the "H-Bomb" burger. (Kirk McKoy / Los Angeles Times / June 30, 2012)

2 tablespoons chopped cilantro

1 tablespoon white vinegar

Salt

In the bowl of a food processor, combine the habanero peppers, garlic, tomatoes, cilantro and vinegar. Process to a smooth paste. Taste and season as desired. This makes a generous 1½ cups relish. Cover and refrigerate for 24 hours to give the flavors time to marry.

Chipotle mayonnaise

1 cup mayonnaise

2 chipotle peppers (canned in adobo sauce), chopped

1 tablespoon adobo sauce

Juice of ½ lime

Salt and pepper

In a food processor, pulse together the mayonnaise, chipotle peppers, adobo sauce and lime juice. Season to taste with salt and pepper, then cover and refrigerate until ready to use. This makes about 1 cup chipotle mayonnaise, which will keep, covered and refrigerated, up to 1 week.

Caramelized onions

3 tablespoons butter

2 tablespoons olive oil

2 1/2 pounds onions, thinly sliced

1/4 teaspoon salt

1/4 teaspoon pepper

2 teaspoons sugar

In a large skillet, preferably cast iron, melt the butter and olive oil over medium-high heat, then stir in the onions. Stir in the salt and pepper and continue to cook, stirring constantly, until the onions begin to soften, about 5 minutes. Stir in the sugar and continue to cook, stirring and scraping the browned bits from the bottom of the pan, until the onions are golden-brown, 20 to 30 minutes.

The H-Bomb burger