In a food processor, pulse the rinsed and drained seitan until it's finely ground.
Transfer the ground seitan to a large mixing bowl.
Add the cottage cheese, breadcrumbs, onion, egg, lemon juice, dill, mint/parsley, cumin, baking soda, allspice, and cinnamon.
Using your hands or a potato masher, mix and mash everything together until well combined and the mixture holds its shape.
Season with salt and pepper to taste.
Cover and chill the mixture in the refrigerator for at least 30 minutes.
Preheat your oven to 350°F / 175°C. Lightly coat a large baking dish with olive oil.
Roll the chilled seitan mixture into golf ball-sized meatballs (this makes about 48) and arrange them in a single layer in the prepared dish.
Bake for 20 minutes until they are lightly browned and firm.
Carefully remove the dish from the oven.
Pour the tomato sauce evenly over the meatballs. If using, sprinkle the crumbled feta cheese on top. Return the dish to the oven and bake for another 30 minutes, or until the sauce is hot and bubbly.
Garnish with extra fresh herbs before serving.
Don't over-process the seitan; a coarse, ground texture is perfect.
Chilling the mixture for at least 30 minutes is crucial for helping the meatballs hold their shape while rolling and baking.