STEP 1: Heat the butter in a frying pan (non-stick is best for eggs).
STEP 2: When the butter bubbles, pour the egg whites.
STEP 3: Measure the spinach loosely packed in the cup.
STEP 4: Add the spinach, and the goat cheese in small clumps.
STEP 5: Fold over once as shown.
STEP 6: Fold over again to form and envelope.
STEP 7: Turn over and cook the other side until golden.