Preheat oven to 400F. Line a large baking sheet with baking paper and set aside.
Add 1 teaspoon olive oil to a large skillet over a medium heat. Once warm add the diced onion and saute about 5 minutes to soften. Add the garlic and cook an additional minute until fragrant. Remove from heat.
Add the onions and garlic to a food processor along with the remaining ingredients. Pulse until a slightly sticky dough forms.
Scoop out the mixture, 1 heaping tablespoon at a time and roll into little balls. Place on your lined baking sheet, leaving about 1 inch space in between each ball. You should end up with about 18-20 balls.
Place in the middle of the oven and bake 25 minutes. Halfway through the cook-time take the lentil balls out and flip.
Once done, let the balls cool for a few minutes, and then mix into a warmed marinara sauce and serve.