1. Bring grits, chicken broth, and next 3 ingredients to a boil in a medium saucepan over medium-high heat; reduce heat to low, and simmer, stirring occasionally, 4 to 5 minutes or until thickened. Stir in butter and cheeses until melted.
2. Gradually stir about one-fourth of hot grits mixture into eggs; add egg mixture to remaining hot grits mixture, stirring constantly. Pour grits mixture into a lightly greased 2 1/2-qt. baking dish.
3. Bake at 350° for 35 to 40 minutes or until golden brown and bubbly around edges. Let stand 5 minutes before serving.