Beet Burgers With Lemon Aioli Recipe
Active time: 45 minutes
Total time: 1 hour 15 minutes
To make beet burgers: Line a baking sheet with parchment paper and set aside. In a small pot, heat 1 Tbsp. oil over medium heat. Add onion and garlic and cook until translucent and softened, about 4 minutes. Add lentils and 1 cup water and bring to a boil. Reduce heat to medium-low and simmer until liquid is absorbed and lentils are just tender, about 15 minutes. (The lentils should not be dry, so add more water during cooking if needed.) Season with 1 tsp. salt, spread out on a large plate, and set aside to let cool completely.
While lentils cool, wipe small pot clean. Add bulgur and ½ cup water and bring to a boil. Reduce heat to medium-low and gently simmer, partially covered, until liquid has absorbed and bulgur is just tender, 8 to 10 minutes. Set aside to let cool completely.
Meanwhile, arrange grated beets in a colander and rinse under cold, running water, tossing, until water is no longer red and runs light pink. Transfer to a clean kitchen towel, wrap snugly, and wring firmly to remove excess moisture. (Note: This will stain your towel pink.) Transfer beets to a large bowl and set aside. You should have about 3 packed cups.
In a food processor fitted with a metal blade, pulse half of lentil mixture with walnuts to make a coarse paste. Transfer to bowl with beets. Add herbs, bread crumbs, eggs, lemon and orange zests, pepper, remaining 1 tsp. salt, reserved bulgur, and remaining lentil mixture. Using your hands, mix very well. Form mixture into 6 (4") patties. Transfer to prepared baking sheet and refrigerate, uncovered, until completely chilled, 3 hours or overnight.
To make lemon aioli*: In a medium bowl, combine egg yolk, garlic, lemon juice, and zest. Whisk vigorously until pale yellow and frothy, about 30 seconds. While whisking constantly, very slowly drizzle in olive and canola oils, incorporating them into yolk mixture a few drops at a time. (If added too quickly, the emulsification may break.) If aioli is very thick, whisk in an additional 1 to 2 tsp. lemon juice to adjust to desired texture, then whisk in salt. Cover and chill until ready to serve.
Preheat oven to 350°. In a large skillet, heat 2 Tbsp. oil over medium-high heat. Add 3 burgers and cook, carefully flipping, until deep golden brown on both sides, 3 to 4 minutes per side. Transfer burgers to prepared baking sheet and carefully wipe skillet clean. Return skillet to heat and repeat with remaining 2 Tbsp. oil and 3 burgers. Bake burgers until completely cooked through, tender on the inside, and deeply golden brown on the outside, about 15 minutes.
Arrange lettuce on the bottom halfof each bun and top with a burger. Add a slice of feta, and dollop with lemon aioli. Top with lentil sprouts and remaining half of bun and serve.
*As a simpler alternative to the lemon aioli, mix 1 cup mayonnaise with 2 Tbsp. lemon juice and 1 tsp. finely grated lemon zest.