Add the oats to a blender and pulse until they are ground into a powder-like consistency. Set aside.
Add all the meatball ingredients in a food processor and blend until well combined. If you don’t have a food processor, add them to a large mixing bowl and mash with a potato masher, a fork or use an immersion blender.
Make balls with your hands (I made 30). Add to a plate and refrigerate for 15 minutes.
Heat a little bit of oil (I used extra virgin olive oil) in a skillet or frying pan and sautée the meatballs over medium-high heat until golden brown. If you don’t eat oil, bake them at 350ºF or 180ºC until golden brown. Set aside.
Add the marinara sauce and the vegetable stock to the skillet or frying pan, stir and bring to a boil.
Cook the meatballs in the sauce over medium-high heat for about 20 minutes, stirring occasionally.
Serve immediately (I added some chopped fresh parsley on top) or keep leftovers in an airtight container in the fridge for 5-7 days.
The nutritional info has been calculated by using 1 tbsp of extra virgin olive oil to cook the meatballs.