Preheat your oven to 400°F and line a baking sheet with parchment paper.
Cut the chicken breast into bite-sized nugget pieces and pat them dry with a paper towel.
In a small shallow bowl, whisk the egg white until it is slightly frothy.
In a separate shallow bowl, combine the almond flour, garlic powder, smoked paprika, and a pinch of salt and pepper.
Dip each chicken piece into the egg white, then dredge it through the almond flour mixture until evenly coated.
Place the nuggets on the prepared baking sheet in a single layer, ensuring they do not touch.
Bake for 15 to 18 minutes, flipping halfway through, until the coating is golden and the chicken is cooked through.
While the nuggets bake, warm the pre-cooked quinoa and place the mixed greens in a serving bowl.
Serve the crispy chicken nuggets over the bed of quinoa and greens, finishing with a squeeze of fresh lemon if desired.