Make the filling: In a medium-small bowl, mix together the quinoa, spinach, feta, red onion, olive oil, lemon juice, garlic, salt, and pepper. Adjust seasonings to taste. (I like to slightly over-season my filling so that it’s flavorful amongst the whole potato.) Chill until ready to use.
Remove the sweet potatoes from the oven and let cool slightly. Slice a wedge lengthwise in each potato and remove to make space for the filling. Add the filling and top with scoops of tzatziki.
Recipe by Love and Lemons at https://www.loveandlemons.com/stuffed-sweet-potatoes/