- Peel and thinly slice potatoes and parsnips.
- Generously butter 13x9 inch casserole dish; rub with garlic.
- Arrange single layer of potatoes in dish.
- Sprinkle lightly with a little of the thyme, salt and pepper.
- Cover with layer of parsnips.
- Sprinkle with seasonings.
- Repeat layer with remaining vegetables.
- Pour in enough cream to come three-quarters up side of dish.
- Place on baking sheet and bake, covered, in 375°F oven for 30 minutes.
- Uncover and bake for 30 minutes longer or until top is brown and crusty and potatoes are cooked through.