Roasted cauliflower and vegetable chowder

medium cauliflower ((approx 350g))

olive oil

salt & pepper

large onion

medium-large carrots

medium-large potatoes

butter

dried thyme

smoked paprika ((optional))

vegetable stock ((1 1/3 cups))

milk ((scant 1 cup))

grated cheese & chopped parsley to serve ((optional))