Heat a skillet or griddle to 300 degrees.
Butter the outside of a slice of bread, and spread goat cheese on the inside slice of bread.
Layer slices of brie, gruyere, and cheddar cheese and top with another slice of bread.
Place on the heated skillet, and cover with a lid to help the cheeses melt together, cooking over low/medium heat.
Flip after a couple of minutes when the bread is golden brown.
Cook again for a couple of minutes, covered, until both sides of the sandwich are golden brown and the cheese is melted.
