1Preheat oven to 200C/180C. Lightly grease a 12-hole muffin pan.
2Sift flour and soda together in a large bowl. Stir in spinach, onion and half of the feta. Combine remaining ingredients in a bowl, whisking well to combine.
3Fold through dry mixture until just combined. Spoon into prepared cases and sprinkle with remaining feta. Bake for 25-30 minutes until cooked when tested with a skewer.
4Tip: you will need a 550g Sweet Potato to make enough puree for this recipe.