Pre heat the oven at 220 deg C and grease a muffin tray.
Mix together the flours, baking powder, salt, cheese, butternut squash, coriander and spinach.
Rub in the butter till the mixture resembles coarse crumbs.
Mix together the egg and the milk.
Add the milk and egg mixture to the flour mixture and bring everything together. Do not overmix. You can use a fork to gather the mixture together before using hands.
Transfer the dough ( it will be quite sticky) to a well floured surface and bring it together with well floured hands.
Shape into 15 -16 craggy balls and arrange in the muffin tray. See notes below.
Brush the tops with a little milk and sprinkle the sesame seeds on top.
Bake in the centre of the pre heated oven for 20-25 minutes or till golden and a toothpick inserted comes out clean.
Cool in the tray for a few minute and serve warm. If serving later, then transfer them to a rack to cool completely before storing in air tight containers and warm them a little before serving.