Directions

1. Cook half of the onion with 1/4 teaspoon salt in oil in a small heavy saucepan over medium heat, stirring occasionally, until golden, 5 to 7 minutes.

2. Add bulgur and water and cook, covered, over low heat until water is absorbed, 15 to 18 minutes.
3. Transfer to a bowl and stir in beans and soy sauce.
4. Pulse bulgur mixture, walnuts, 1 tablespoon True Lime Garlic & Cilantro, cumin, cayenne, a rounded 1/4 teaspoon salt, 1/2 teaspoon pepper, and remaining onion in a food processor until finely chopped.
5. Form rounded 1/2 cups of mixture into 4 (3 1/2-inch-diameter) patties. Chill for at least 10 minutes.
6. While patties chill, stir together mayonnaise and 1 tablespoon True Lime, Garlic & Cilantro. (Add more if you want a stronger flavor).
7. If cooking patties on the stove, heat 1 tablespoon oil in a heavy 12-inch skillet over medium heat until the oil shimmers, then fry each patty, carefully turning once until golden brown. (About 8 minutes).
8. If grilling patties, prepare a grill for medium-hot charcoal or medium heat for gas. Put the perforated grill sheet on the grill and preheat for 10 minutes. Brush patties all over with oil. Oil grill sheet, then grill burgers on grill sheet, carefully turning once until golden brown, about 8 minutes.
9. Serve burgers open-faced on toast with lime mayonnaise.