HEAT oven to 375°F.
COOK mushrooms and onions in large nonstick skillet sprayed with cooking spray on medium-high heat 5 min. or until crisp-tender. Remove from heat; stir in spinach.
BEAT eggs, milk and dressing in medium bowl with whisk until well blended. Add spinach mixture and cheese; pour into crust. Top with bacon.
BAKE 50 min. or until center is set and top is golden brown.Kraft Kitchens Tips Serving Suggestion Serve this entree with a mixed green side salad tossed with your favorite KRAFT Light Dressing, a whole grain roll and fresh fruit for dessert. To thaw frozen spinach Place spinach block in colander in sink. Run hot water over spinach until thawed; press out any excess liquid. Creative Leftovers A slice of quiche, served warm or cold with a tossed salad, is a perfect lunch to take to work the next day.