Rinse the lentils under cold water until clear. Boil 4 cups of water in a pot and add lentils. Simmer for 20-25 minutes until tender, then drain and cool.

In a skillet, heat olive oil over medium. Sauté finely chopped onion and minced garlic for about 5 minutes until onion is translucent.

In a bowl, combine cooked lentils, sautéed onion and garlic, panko breadcrumbs, the beaten egg, parsley, oregano, lemon zest, and season with salt and pepper. Mix well.

Preheat the oven to 400°F (200°C). Roll approximately 2 tablespoons of the mixture into balls and place them on a lined baking sheet.

Bake the meatballs for 25-30 minutes, flipping halfway through for even browning until golden and crispy.

Let the meatballs cool slightly after baking, then serve hot with tzatziki sauce for dipping.