1. Start by preheating your oven to 375°F (190°C).
2. Heat some oil in a skillet, add the chopped onion, and saute until it becomes translucent and fragrant, about 3-4 minutes. Then add garlic and cook for another 2-3 minutes. 
3. Combine the drained and rinsed canned lentils, oat flour, sauteed onion and garlic, parsley, nutritional yeast, smoked paprika, Italian mixed herbs, salt, black pepper, and tomato puree in a large mixing bowl.
4. Use a potato masher, a fork or a food processor to mash and blend the ingredients until they form a cohesive mixture. You can leave some texture for a more rustic feel or process until smoother for a more uniform texture. 
5. Let it rest for 10 minutes to make it easier to shape the balls. 
6. Shape the lentil mixture into meatball-sized balls using your hands. You can wet your hands slightly to prevent sticking.
7. Place the lentil meatballs on a baking sheet lined with parchment paper.
8. Lightly brush each meatball with oil or use a cooking spray to help develop a crispy and golden-brown exterior during baking. 
9. Bake in the preheated oven for about 25-30 minutes or until the meatballs are firm and slightly crispy outside.

Serve the lentil meatballs with your favourite tomato sauce and pasta, on sub rolls for meatball subs, or as an appetiser with dipping sauce.

For the Spaghetti:

1. While the lentil meatballs are in the oven, cook the pasta according to the package instructions until al dente. Drain and set aside.
2. Heat your favourite vegan tomato sauce in a separate pot over medium heat.
3. Once the lentil meatballs are cooked and the sauce is heated, add the meatballs to the sauce and simmer for a few minutes to combine the flavours.
4. Serve the lentil spaghetti meatballs over cooked spaghetti. Garnish with fresh basil leaves and vegan Parmesan cheese if desired.