Grate 1 head cauliflower on the large holes of a box grater. Cook in butter in an ovenproof skillet over medium-high heat, stirring, until golden, 8 minutes. Add 1 cup heavy cream; season with nutmeg, salt and pepper. Cook until thickened, 3 to 5 minutes. Top with 1 cup shredded gouda. Broil until browned, about 3 minutes.