Prepare the potato base:
- Boil the cubed potatoes in salted water for 20 minutes until fork tender. Drain well.
- Mash the potatoes with a potato masher until smooth. Season with salt, pepper, smoked paprika, and mixed herbs.
- Let cool slightly, then stir in the beaten eggs and flour until well blended. Set aside.
Make the ground beef filling: 4. Heat the vegetable oil in a large skillet over medium heat. Add the ground beef and cook, breaking it up with a spoon. 5. Add the chopped onion and cook until softened, about 5 minutes. 6. Stir in the minced garlic and cook for 1 minute until fragrant. 7. Add the grated carrot and chopped bell pepper. Cook for 5 to 7 minutes until the vegetables are tender. 8. Add the chopped parsley and green onions. Season with salt and pepper. Mix well and remove from heat.
Assemble the Stuffed Potato Balls: 9. Preheat oven to 350°F (180°C). Grease a baking dish with vegetable oil. 10. With wet hands, form a potato patty in your palm. Add 2-3 spoonfuls of beef filling to the center. 11. Fold the edges over and seal to form a large ball, or place another potato patty on top and seal the edges. 12. Repeat to make 4 large stuffed potato balls. Place in the prepared baking dish.
Prepare the mushroom sauce: 13. Heat the butter in a skillet over medium heat. Add the chopped onion and cook until golden. 14. Add the minced garlic and cook for 1 minute. Add the chopped mushrooms and cook until softened. 15. Pour in the heavy cream and simmer for 2-3 minutes. Add half of the grated mozzarella and stir until melted. 16. Season with salt and pepper. Remove from heat.
Bake and Finish: 17. Pour the mushroom sauce over the potato balls in the baking dish. 18. Bake for 30 minutes. Remove and top with the remaining mozzarella cheese. 19. Bake for an additional 10 minutes until the cheese is golden brown and bubbly.
