Arrange the sweet potato slices in the bottom of a deep dish pie plate. I do this in a circular pattern, overlapping them slightly. Come up the sides of the pie plate a little with the slices. These will form your crust for the quiche.
Drizzle or spritz the sweet potatoes with the olive oil. Bake for 15-20 minutes or until the sweet potatoes are tender. Set this aside.
Reduce the oven temperature to 375 degrees.
Meanwhile, saute the bacon in a skillet over medium low heat until golden and crisp. With a slotted spoon, transfer the bacon to a plate lined with paper towels, leaving about 2 tablespoons of the drippings in the skillet.
Saute the onion in the bacon drippings until they are translucent.
Add the minced garlic, and continue to cook until the onions and garlic are just tender.
Add in the spinach and cook until just wilted. About 2 minutes. Remove from the heat.
Arrange the spinach mixture over the top of the sweet potato crust.
In a bowl, beat the eggs, basil, salt and pepper. Pour the mixture over the top of the contents of the pie plate.
Sprinkle the bacon all over the top.
Bake for 30-35 minutes or until the eggs are set. The quiche will puff up as it bakes.
Allow the quiche to rest 5-10 minutes before serving. As it rests, it will sink back down in the center.