Buttery avocados make any sandwich better, and they put this burger over the top. Grass-fed beef can be lean, but the sliced avocado and spicy chipotle mayonnaise ensure that this burger is a luscious, moist, flavor-packed experience.
- 1 1⁄2 pounds (750 g) grass-fed ground beef chuck
- Scant 1 1⁄2 teaspoons kosher or sea salt
- 3⁄4 teaspoon garlic powder
- Freshly ground black pepper
- 1⁄4 cup plus 2 tablespoons (90 ml) mayonnaise, homemade or store-bought
- 1 tablespoon extra virgin olive oil, if using store-bought mayonnaise
- 1 small clove garlic, grated with a rasp grater or very finely minced
- 1 1⁄2 teaspoons very finely minced chipotle chile in adobo, or more to taste
- 1 tablespoon extra virgin olive oil
- 4 hamburger buns, split
- 1 ripe but firm small avocado
- 1⁄2 lime
- About 1⁄2 cup (20 g) loosely packed fresh cilantro leaves
- 4 large, soft lettuce leaves
Make the burgers: Put the beef in a bowl and add the salt, garlic powder, and several grinds of black pepper. Mix quickly with your hands; try not to overwork the mixture. Divide into four equal portions, each 6 ounces (185 g), and shape into balls. Flatten each ball into a round patty about 3∕4 inch (2 cm) thick. Make the patties a little thinner in the center. They shrink a bit when cooked, and this step ensures they will be of even thickness after cooking. Place them on a tray and refrigerate.
Make the mayonnaise: Put the mayonnaise in a small bowl. If it is store-bought, whisk in the olive oil to improve the flavor. Whisk in the garlic and chile. Taste and add more chile if you like. Cover and refrigerate until needed.
Preheat the broiler. Heat a large cast-iron frying pan over medium heat. Add the olive oil and swirl to coat the bottom of the pan. When the oil is hot, add the patties and fry until nicely browned and done to your taste, flipping them with a spatula two or three times and adjusting the heat to keep them from getting too crusty on either side. For medium doneness, the total cooking time will be about 10 minutes.
Set the burgers aside on a platter to rest for about 3 minutes. Meanwhile, toast the buns, cut side up, under the broiler. Halve, pit, and peel the avocado and slice thinly.
Spread chipotle mayonnaise on both halves of the toasted buns. Top the bottom half of each bun with a burger. Divide the avocado slices evenly among the burgers. Sprinkle the avocado lightly with salt and a squeeze of lime. Top with a tuft of cilantro leaves, then with a lettuce leaf, and finally the top half of the bun. Cut in half with a serrated knife and serve immediately.