Ovens and potatoes vary so you may need to add a bit of stock part way through the cooking. Sometimes we do....and sometimes we don't.
Pre heat oven to 400. Spread 1 TBSP soft butter over bottom and sides of 9” x 12” casserole dish. In a small bowl mix grated cheese, thyme, salt and pepper.
Bake uncovered for 30 minutes, tilt the dish and spoon stock over potatoes. Reduce heat to 350. Check to see whether or not the potatoes need a bit more stock and add at this time. Bake for another 35 - 45 minutes. Potatoes should be fork tender and golden brown. Let rest 10 minutes and serve.