makes 12 muffins 

1 Tbsp. unsalted butter
2 Tbsp. olive oil
2½ cup pumpkin or butternut squash, cut into ½-inch dice
Salt and pepper to taste
3 Tbsp. sunflower seeds
¾ cup freshly grated Parmesan
½ cup cubed feta
2 tsp. whole-grain mustard
2 large eggs, lightly beaten
¾ cup milk
2 cup flour
4 tsp. aluminum-free baking powder
1 tsp. fine-grain sea salt 

Set the rack in the top third of your oven; preheat the oven to 400°. Use the butter to grease a 12-cup muffin pan and set aside (or use paper liners). 

Sprinkle the olive oil and some salt and pepper over the squash. Toss well and transfer to a rimmed baking sheet; arrange in a single layer and bake for 20–25 minutes or until tender. Set aside to cool. 

Transfer the squash to a large mixing bowl and mash. Add the sunflower seeds, Parmesan, feta, and mustard. Gently fold together. 

In a separate bowl, beat the eggs and milk together; add to the squash mixture. Sift the flour and baking powder onto the mixture, add salt and a generous pinch of freshly ground black pepper, and use a rubber spatula to gently fold the batter just until the flour is incorporated. 

Spoon the mixture into the prepared muffin pan, filling each cup almost full and top with feta. Bake for 15–20 minutes or until the tops and sides of the muffins are golden and the batter is set up completely. Let cool for a couple minutes, then turn out onto a cooling rack.