Precooked lentils are a convenience item we love, saving nearly 30 minutes of simmering. Look for plain, steamed lentils (such as Melissa's), in the grain aisle. The food processor not only combines the patty ingredients; it coarsely chops the lentils so the finished cakes will hold their shape in the pan. While we love fat-free and reduced-fat Greek yogurt, go ahead and use full-fat here for a richer mouth feel and less tang in the sauce.
How to Make It
Heat 1 1/2 teaspoons oil in a large nonstick skillet over medium. Add onion and garlic; sauté 3 minutes. Place onion mixture, oats, 1 tablespoon vinegar, 3/4 teaspoon salt, pepper, eggs, and lentils in a food processor; pulse 3 to 4 times. Shape mixture into 12 patties.
Heat 1 1/2 teaspoons oil in pan over medium-high. Add 6 patties to pan; cook 2 minutes on each side. Remove from pan. Repeat with 1 1/2 teaspoons oil and remaining 6 patties.
Combine remaining 1 tablespoon vinegar and remaining 1 tablespoon oil in a large bowl, stirring with a whisk. Add arugula and spinach; toss.
Combine remaining 1/4 teaspoon salt, yogurt, juice, and mint in a bowl. Divide arugula mixture among 4 plates; top each serving with 3 patties and 2 tablespoons yogurt mixture. Sprinkle evenly with pistachios.