Rinse and drain the kidney beans. Put them in a medium bowl and mash them well with a fork. In a medium pan, heat some oil and sauté the onions for 3 minutes. Add the minced garlic and the mushrooms and cook for another 2 minutes. Add it to the mashed beans together with the spices, tomato paste, soy sauce, and oats. Put the sunflower seeds in a food processor and pulse until a fine meal is achieved. Add to the bean mixture and combine well. Season with salt and pepper. Form about 12-14 vegan meatballs.
Preheat the oven to 350 °F. Line a baking sheet with parchment paper, equally place the meatballs on top of it, and bake them for about 15 minutes.
Serve the vegan meatballs on Italian sub rolls or baguette and top them with your favorite marinara, vegan cashew Parmesan, and sprinkle them with fresh parsley. Enjoy!