Mix together butter, garlic powder, garlic salt and green onions. Spread it evenly among the 4 slices of bread and then place them on a foiled lined baking sheet.
Place bread in the oven for 5-7 minutes, or until the bread is beginning to brown/crisp up. Take out the bread and sprinkle with the mozzarella cheese. Return to oven for another 5 mins until cheese is melted. Enjoy!!