Cook the lentils according to package directions.
Drain thoroughly and set aside.
While lentils cook, heat 2 Tbs. olive oil in a skillet over medium heat.
Add the onion and bell pepper and sauté for 7 minutes until soft.
Stir in the garlic and cook for 1 minute more until fragrant.
In a food processor, combine the chickpeas, parsley, olives, eggs, cumin, coriander, salt, and pepper.
Blend for about 2 minutes, scraping the sides as needed, until a smooth paste forms.
In a large bowl, combine the cooked lentils, the sautéed vegetables, and the chickpea mixture.
Stir in the breadcrumbs, grated carrots, and baking powder until everything is well incorporated.
Shape the mixture into 8 equal-sized patties.
Place them on a parchment-lined baking sheet, separating layers with plastic wrap if needed, and freeze for at least 30 minutes until firm.
While the patties freeze, make the tzatziki sauce by combining the yogurt, shredded cucumber, garlic, lemon zest, mint, and parsley in a small bowl.
Refrigerate until ready to use.
Preheat your grill to high.
Brush the frozen patties with olive oil and grill for 6 minutes on each side, until nicely charred and heated through.
Serve immediately with the tzatziki sauce.
Don't skip the freeze!
Chilling the patties for at least 30 minutes is the secret to a burger that holds its shape on the grill. You can freeze them for up to 3 months for a quick meal.
