Instructions

• Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add 1 cup diced yellow onion and 8 ounces roughly chopped cremini mushrooms. Sauté, stirring occasionally, until the onion is translucent and the mushrooms are tender and their released liquid has mostly evaporated, about 8–10 minutes. Remove the pan from the heat and let the vegetables cool until they are warm but not hot to the touch.
• While the vegetables cool, preheat the oven to 400°F (204°C) and line a large baking sheet with parchment paper.
• In the bowl of a 12-cup food processor, add 1 ½ cups cooked lentils (brown or green), ½ cup rolled oats, ½ cup Parmesan cheese, 1 large egg, 1 ½ teaspoons dried oregano, ½ teaspoon garlic powder, 1 teaspoon fine sea salt, and ¼ teaspoon ground black pepper.
• When the onion and mushrooms have cooled to warm (not hot), add them to the food processor bowl.
• Secure the lid and pulse the mixture several times until it is relatively uniform but not pureed. The mixture should hold together when pressed between your fingers and still show small pieces of onion and oats.
• Use a heaping tablespoon or a cookie scoop to portion the mixture. Roll each portion between your hands to form a ball and place it on the prepared baking sheet. Continue until all the mixture is used; you should have approximately 24 meatballs.
• Bake the meatballs in the preheated 400°F oven for 15 minutes. If the edges are not yet dry or the meatballs do not smell fragrant, bake up to 5 minutes longer.
• Remove the baking sheet from the oven and let the meatballs cool on the sheet; they will feel tender when hot and will firm up as they cool.
• To serve, simmer the meatballs in your favorite marinara sauce and serve over pasta or as desired.
• Store any leftovers in an airtight container in the refrigerator for up to 5 days.