More and more people are cooking with ground buffalo meat because it's lower in fat than beef chuck. That very asset can turn into a liability if the meat is cooked too long, so here, sauteed chopped portobello mushrooms contribute additional moistness and flavor. Don't reach for the ketchup: A crisp slaw of celery and apples in a mustard dressing is a piquant surprise.
- 1 medium onion, chopped
- 10 ounces portobello mushrooms, trimmed and quartered
- 2 tablespoons plus 2 teaspoons olive oil, divided
- 1 pound ground buffalo
- 2 celery ribs
- 1/2 Granny Smith apple, cored (left unpeeled)
- 1 tablespoons mayonnaise
- 1 1/2 teaspoons cider vinegar
- 1 teaspoon olive oil
- 1 teaspoon whole-grain mustard
- Rounded 1/4 teaspoon sugar
- Equipment: an adjustable-blade slicer fitted with 1/8-inch julienne blade
- Accompaniment: 4 hamburger buns or kaiser rolls, split and toasted
Cook vegetables for burgers:
Pulse onion and mushrooms in a food processor until finely chopped. Heat 2 tablespoons oil in a 10-inch heavy skillet over medium heat until it shimmers. Add mushroom mixture, 3/4 teaspoon salt, and rounded 1/4 teaspoon pepper and cook, stirring occasionally, until vegetables begin to brown and liquid has evaporated, 8 to 10 minutes. Transfer to a bowl and cool to warm, stirring occasionally, about 15 minutes.
Meanwhile, make slaw:
Cut celery and apple into 2-inch-long thin julienne with slicer.
Whisk together mayonnaise, vinegar, oil, mustard, sugar, rounded 1/8 teaspoon salt, and 1/8 teaspoon pepper in a medium bowl. Add celery and apple, tossing to coat. Let stand 15 minutes to develop flavors.
Finish and cook burgers:
Mix buffalo into cooled mushroom mixture with your hands until well combined. Form into 4 (4-inch) patties.
Heat remaining 2 teaspoons oil in a 12-inch heavy skillet over medium-high heat until it shimmers. Cook burgers, turning once, about 8 minutes total for medium-rare.
Serve burgers, topped with slaw, on buns.