Peel and boil the potatoes in salted water for about 15 minutes, then drain and mash until smooth.

In a skillet, heat olive oil and sauté the onion until translucent, then add mushrooms and garlic, cooking until browned.

Combine mushroom mixture with mashed potatoes, cheese, and egg, mixing until well combined.

Shape the mixture into patties about 3 inches in diameter.

Coat each patty with breadcrumbs on both sides.

Fry the cakes in heated olive oil for 4-5 minutes on each side until golden brown.

Transfer the cakes to paper towels to drain excess oil before serving.

Sprinkle with fresh parsley before serving warm.