Preheat oven to 230°C (or 210°C fan bake). Dust a baking tray with gluten free flour or line with baking paper. Bring a kettle to the boil.
To a heatproof bowl, add broccoli and a pinch of salt and cover with boiling water. Cover with a plate and leave to cook for about 4 minutes. Drain well.
Place flour, baking powder, paprika and a pinch of salt in a bowl. Add grated butter, using your fingertips, rub butter into flour until it resembles breadcrumbs. Fold through broccoli, spinach, spring onion and feta.
Add milk, using a butterknife, quickly mix until a soft dough forms.
Turn dough out onto a floured surface and knead lightly if needed to pull dough together. Form dough into a rectangle shape and transfer to the lined baking tray. Cut into 9 pieces and spread out slightly. Top with grated cheese. Bake for 15-20 minutes, until golden and risen.