Preheat oven at 3705F

Using a knife, cut sourdough bread in squares (see video). Start cutting lines lengthwise, then width wise through the crust, but not all the way through.

In a bowl, mix melted butter, garlic, and chopped spinach. Set aside

Fill each cut with cheese.

Pour butter mixture on top of the bread.

Place foil on baking sheet. Use another piece of foil to cover bread. Bake covered at  350F for 15 minutes.

Uncover, and bake again for about 6-7 minutes or until cheese melts.