Heat a large skillet with the butter over medium high.
Add the pearl onions face down.
Add the green beans. Season with salt, garlic powder, and sugar. (About a teaspoon each)
Stir occasionally, but not too often. The key is to let them sit long enough to brown, without burning. The more you stir, the less browning occurs. Find a balance.
Add more butter on top if needed and stir.