Preheat oven to 375° F. Lightly coat a twelve-cup muffin tin with spray. Set aside. Squeeze moisture from sweet potatoes using a clean kitchen towel. Combine sweet potatoes and 2 tsp. oil. Season with salt and pepper if desired. Divide evenly between prepared muffin cups; press sweet potato mixture into bottom and sides of muffin cups. Bake for 14 to 16 minutes, or until edges are golden brown. Set aside. Heat remaining 1 tsp. oil in medium nonstick skillet over medium-high heat. Add onions and broccoli; cook, stirring frequently, for 4 to 6 minutes, or until onion is translucent. Remove from heat. Set aside. Place eggs in a large bowl; whisk to blend. Add onion mixture; mix well. Evenly pour egg mixture into muffin cups. Evenly sprinkle with cheese. Bake for 15 to 18 minutes, or until a toothpick inserted into the center of cups comes out clean.