Preheat your oven to 350°F and lightly grease a standard 6-cup muffin tin with a little extra sesame oil or cooking spray.
Place a skillet over medium heat and add the ground turkey, cooking until browned and crumbled through.
While the turkey cooks, finely chop the fresh spinach, shiitake mushrooms, and green onions.
In a large mixing bowl, whisk the eggs together with the ground flaxseed, tamari, toasted sesame oil, garlic powder, ground ginger, sea salt, and black pepper.
Stir the cooked turkey, chopped spinach, mushrooms, and green onions into the egg mixture until well combined.
Distribute the mixture evenly among the 6 muffin cups, filling each nearly to the top.
Bake for 20 to 25 minutes, or until the eggs are set in the center and the tops are slightly golden.
Allow the bites to cool in the tin for 5 minutes before removing; store in the refrigerator for a quick make-ahead high-protein breakfast.