Between the eggs and the sweet potatoes, this is one filling (not to mention scrumptious) frittata.
Mix sweet potato cubes with two tablespoons olive oil. Season with salt and pepper to taste.
Bake in preheated 400 degrees Fahrenheit (200 degrees Celsius) oven, until cubes are soft and slightly caramelized. Note: This step can be done in advance.
Beat eggs and season with salt and pepper. Add diced pepper and chopped chives.
In a deep pan, sauté onion and garlic in one tablespoon olive oil over medium flame.
Add sweet potato. Add egg mixture. Cover and cook over low flame, about 15 minutes, until frittata is set.
Remove from flame and let sit 10 minutes before serving. For an impressive presentation, use a Teflon pan and flip frittata over!