In a large pot, bring salted water to a boil. Add the diced potatoes and cook until tender, about 15-20 minutes. Drain and set aside.

In a skillet, melt the butter over medium heat. Whisk in the flour and cook for 1-2 minutes until golden.

Gradually whisk in the milk, stirring constantly until the mixture thickens, about 5-7 minutes.

Stir in the garlic powder, onion powder, salt, and pepper. Remove from heat.

Add the cooked potatoes to the sauce and stir to coat evenly.

Transfer to a serving dish, sprinkle with shredded cheddar cheese, and serve warm.