1. Mix 1 package (10 oz.) frozen chopped spinach (thawed and squeezed dry) with 3/4 cup shredded fontina cheese, 1/8 teaspoon ground nutmeg, and 1/2 cup cooked crumbled pork sausage.
2. Start with 6 sheets filo dough (about 12 by 18 in.) and 1/3 cup butter or margarine, melted. Lay 1 filo sheet flat (cover remaining filo with plastic wrap to prevent drying) and brush lightly with butter. Top with another filo sheet and brush lightly with more butter. Repeat to stack remaining filo.
3. Cut filo stack into 6- by 12-inch strips. Divide filling among strips, mounding at one end; roll from filling end to enclose, tucking sides under. With seam down, gently transfer packets to a buttered baking sheet (11 by 14 in.).
4. Bake in a 400° oven until golden brown all over, 13 to 15 minutes.