For the spinach feta toast, defrost the spinach leaves and squeeze well. If possible, cut the feta into 2 – 3 slices or crumble.
Butter one side of each toast slice, place a slice of cheese on top and top with the squeezed spinach leaves. Season with pepper and garlic salt.
Place the feta on top and cover with the second slice of toast. Toast in a plate griller until desired brownness.