PREHEAT oven to 375°F. Lightly press hash browns into greased 9-inch pie plate to form crust. Sprinkle with 1/2 cup of the cheese; top with mushrooms and broccoli.
BEAT eggs, milk, thyme, onion powder and pepper with wire whisk until well blended. Pour over broccoli. Sprinkle with remaining 1/2 cup cheese.
BAKE 35 min. or until center is set and top is golden brown.