Start by boiling whole potatoes until they are soft, then let them cool down before pressing them through a potato masher. Mix in starch, rice flour, salt, and pepper, and set aside.

Next, in a medium pan, heat up some olive oil and sauté peppers and onions for 5-7 minutes. Add mushrooms and cook for an additional 10 minutes. Then, mix in crumbled tofu and cook for another 5 minutes. Add spinach to the mixture and cook for 2-3 minutes. Season with garlic powder, Italian herbs, salt, and pepper to taste. Let the filling cool down slightly.

Now it's time to assemble the stuffed potato cakes. Divide the potato mixture into 9 equal balls, then flatten each ball out and add a heaping tablespoon of filling in the center. Carefully pinch the edges of the potato mixture together to cover the filling and form a patty.

Finally, cook the potato patties in vegetable oil until they are golden on both sides. This will give them a delicious crispy texture that pairs perfectly with the flavorful filling.