Heat oil for sautéing in a large frying pan. Sauté onions until translucent and add spinach, mushrooms, garlic, and cilantro. Season well with salt and pepper.

Remove from heat and add to the mashed potatoes, along with bread crumbs and egg. Refrigerate the mixture for one hour.

Scoop out one and a half tablespoons of the potato mixture and form into a log. Continue until you have 24 logs. Freeze for up to one hour to hold the shape.

Prepare three bowls with the flour, the eggs, and the bread crumbs for the coating. When the logs are firm, roll in flour, then in beaten eggs, and last in bread crumbs.

Heat oil for frying in a large frying pan. Fry logs about four to five minutes on each side, until nicely browned.