In a large bowl, combine the cooked millet, chopped onion, beaten eggs, minced garlic, sage, and salt.
Mix well.
Stir in the chopped spinach, breadcrumbs, feta cheese, and golden raisins until just combined.
Let the mixture rest for 5 minutes to allow the breadcrumbs to absorb moisture.
Test the mixture by pinching a small amount; it should hold its shape. If it feels too wet, add more breadcrumbs, one tablespoon at a time.
Form the mixture into 12 compact patties, using about ¼ cup for each.
Heat the olive oil in a large skillet over medium heat. Carefully place half of the fritters in the pan, ensuring they don't touch.
Cover and cook for 5-7 minutes, until the bottoms are golden brown and crisp.
Gently flip the fritters and cook uncovered for another 5 minutes, or until the second side is also beautifully browned.
Transfer to a plate and repeat the process with the remaining fritters.
