This is a tasty quiche that's gluten free, since the crust is made from sweet potatoes which I found on the Eating Well website which includes a video. 

Ingredients:

Cooking spray
2 medium sweet potatoes, peeled
​   ( cut into 1/8-in thick slices.)
1 tsp. canola oil
1/2 cup sliced onion
1 (5 ounce) bag fresh baby spinach
1/2 cup low-fat milk

1/4 tsp kosher salt
1/4 tsp freshly ground black pepper
1/4 tsp freshly ground blackpepper
1/4 tsp crushed red pepper
4 large eggs 
2 large egg whites
1 1/2 oz feta cheese, crumbled (about 1/3 cup)

Directions:

   Preheat oven to 350 degrees.
​   Coat a 9-inch pie plat with cooking.  Layer sheet potatoes in slightly overlapping concentric circle on the bottom and upside of plate, cutting slices in half to fit (rounded side up) around the sides.  Coat potatoes with cooking spray.  Bake in a preheated oven for 20 minutes or until potatoes are slightly tender.  Place pan on a wire rack.  Increase oven temperature to 375 degrees.
    Heat a large nonstick skillet over medium heat and add oil and onion, sauté 3 minutes.  Add spinach, sauté 3 minutes and remove from head: cool.
    Combine milk, salt, black pepper, crushed red pepper, eggs, and egg whites in a medium bowl: stir with a whisk.  Arrange spinach mixture in crust; put egg mixture over spinach.  sprinkle with feta.  Bake at 375 degrees for 35 minutes or until egg mixture is set.  Let stand 5 minutes; cur into 8 wedges.  (Calories in 2 wedges about 200 calories and 13 grams of protein.