4 1/2 tablespoons butter
2 large potatoes, cut into 1/2-inch cubes
1/2 onion, diced
2 cloves garlic, minced
1 1/2 tablespoons butter
Melt 4 1/2 tablespoons butter in a large skillet over medium-high heat; cook and stir potatoes until golden brown, 10 to 15 minutes.
Meanwhile, melt remaining 1 1/2 tablespoons butter in another skillet over medium heat; cook and stir onion and garlic until tender, about 5 minutes. Reduce heat to medium-low and continue cooking until garlic is lightly browned, 5 to 10 minutes more. Stir onion mixture into potatoes.
Cook and stir potatoes and onion until potatoes are tender, about 10 minutes more.