Pre-heat the oven to 220C/Gas mark 8.
Make up the bread mix or dough according to the instructions, divide into 4 and leave to rise.
Place the squash, onion, pepper and mushrooms on a shallow baking tray and drizzle with the oil. Add the sprigs of thyme and roast in the oven for 30 minutes until soft but not charred.
Roll out the 4 pieces of dough into 20 cm rounds and place on oiled baking sheets.
Spread a very thin layer of tomato ketchup across each base.
Divide the roasted vegetables between the bases and top each with blue cheese and goats cheese.
Bake in the oven for 20 minutes until the pizza bases are golden and the cheese very well melted.