Cauliflower, Potato and Cheddar Bake

INGREDIENTS

1/2 tbsp

unsalted butter

3/4 lb

Yukon Gold potatoes (about 3 medium, peeled and sliced 1/4 inch thick)

salt and pepper

1/2

small head of cauliflower (~1 pound), sliced 1/4 inch thick

2 tsp

fresh thyme leaves, chopped plus more for (optional) garnish

3/4 cup

shredded sharp cheddar

scant 1/4 cup of milk or chicken broth