Cauliflower Pithivier in Gluten-free Cheddar Puff Pastry

Name: Cauliflower Pithivier in Gluten-free Cheddar Puff Pastry
Prep time: 55 min
Cook time: 2 h 10 min
Total time: 2 h 10 min
Yield: 4 portions
Ingredients: 150 g Cheddar cheese; 250 g gluten-free plain white flour; 200 g unsalted butter; 120 g water; 1 tsp xanthan gum; ½ tsp fine sea salt; 400 g cauliflower; 2 Tbsp olive oil; 10 fresh sage leaves; 1 - 2 garlic cloves; 80 g red onions; 20 g gluten-free plain white flour; 200 g milk; 2 tsp Dijon mustard; ¾ tsp fine sea salt; 2 pinches ground black pepper; 40 g pine nuts; 1 medium egg