- For chutney:
- 1/4 cup cider vinegar
- 2 tablespoons pure maple syrup
- 1 large garlic clove, minced
- 1 tablespoon finely grated peeled fresh ginger
- 1/2 teaspoon ground cumin
- 1/8 teaspoon dried hot red pepper flakes, or to taste
- 1 plum tomato, seeded and finely chopped
- 1 small green (unripe) tomato, seeded and finely chopped
- 2 tablespoons chopped fresh cilantro
- For burgers:
- 1 1/2 pounds lean ground lamb
- Prepare grill for cooking.
- Make chutney: Boil vinegar, syrup, garlic, ginger, cumin, and red pepper flakes in a small saucepan until thickened and reduced to about 2 tablespoons, 2 to 3 minutes (watch carefully). Remove from heat and stir in tomatoes and salt to taste. Stir in cilantro just before serving.
- Make burgers: Form lamb into 4 (3/4-inch-thick) patties and season with salt and pepper. Grill on a lightly oiled rack set 5 to 6 inches over glowing coals about 4 minutes on each side for medium-rare.
- Serve burgers with chutney.