Using a mandolin, slice the sweet potato into thin slices. Set aside.
In a large bowl, combine quinoa, salsa, and corn.
In a large skillet, heat about 3 Tbsp of oil. When hot, add in vegetables, and sauté with salt and pepper until lightly softened–about 4-5 minutes. Remove from heat and add to bowl of quinoa, salsa, and corn.
In the same skillet, cook the ground turkey with the garlic powder, cumin, chili powder, salt and pepper, and coriander. When fully cooked, add to bowl of quinoa and veggies.
Mix all ingredients together, and taste to see if additional salt and pepper is needed.
Next, in a large oval or rectangular 9X13 inch pan, grease the bottom and layer sweet potato slices. Next spread out about half of the quinoa mixture and top with cheese. Repeat the process once more (layer potatoes, quinoa, and cheese), then top with one final layer of potato slices and a heaping amount of cheese. Cover with foil.
Bake in the center of the oven until sweet potatoes are cooked through, about 40-45 minutes, then remove foil and bake until sweet potatoes are tender, 15 minutes more. Let rest 10 minutes, then serve hot with desired toppings.