Heat oil in a large frying pan. Add onions and sauté over low to medium heat until golden, about 15 minutes.

Raise heat to high and add the diced duck fry. Continue sautéing for an additional five minutes, stirring occasionally. Remove from heat.

Meanwhile, peel and dice the potatoes. Place in a six-quart pot and cover with water. Bring to a boil over high heat and boil for 15–20 minutes until fork tender. Drain.

Mash potatoes finely. Add half of the sautéed onion and duck fry mixture to the mashed potatoes. Add in the salt, pepper, onion powder, and mayonnaise and mix well. Transfer the potato mixture to a 9- x 13-inch (20- x 30-cm) baking dish or divide evenly among 10 ramekins.

Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).

Place the crushed garlic and cauliflower in the frying pan. Sauté for five minutes over medium heat. Add the seasoned panko crumbs and mix well.

Arrange cauliflower mixture over potato mixture in the pan or divide evenly among the ramekins.

Bake for 30 minutes for the 9- x 13-inch (20- x 30-cm) pan or 18–20 minutes for the ramekins.