1. Melt butter in large skillet over medium heat. Stir in flour; cook, stirring, 1 minute or until golden.
2. Gradually stir in milk. Bring to simmering over medium-high heat; cook, stirring constantly, 2 to 3 minutes or until thickened. Stir in salt, red pepper, nutmeg, ham and scallions. Remove from heat.
3. Bake in 400 degrees F oven 30 minutes or until heated through.