Cook the lentils according to package instructions and set aside to cool. Cook in vegetable broth for extra flavor if desired.
Preheat the oven to 375 degrees Fahrenheit.
Roughly chop the onion, mince the garlic and add to a large pan with the oil.
Saute for about 5-7 minutes or until golden lightly brown.
Add in the mushrooms and cook down for 5-10 minutes or until softened.
Add to a food processor with all remaining ingredients and pulse until combined. Careful not to over mix, you want to retain some texture so it's meaty. If the mixture looks too wet, add in more flour or breadcrumbs until easy to handle (you can also add in about 1 tablespoon of cornstarch or another starch to absorb more moisture). It should be firm, but not dry. Taste and adjust any seasonings as desired. I usually add extra basil, but it's up to you! Keep in mind the flavors will deepen as they bake.
Use a spoon or a small cookie scoop (my preference) to form into roughly 1 to 1 1/2 inch balls. Add to a baking tray lined with parchment paper. Don't worry if they aren't perfect circles, we can reshape in a bit! Bake for 15 minutes, carefully re-shape with your hands as needed and flip over.
Bake an additional 20-25 minutes or until golden brown.
You can then enjoy as is with pasta & sauce (delicious with my pomodoro sauce) or transfer to pan and lightly saute with olive oil, then top with sauce and let simmer. Enjoy!