Step 1

Preheat the oven to 400°F/200°C. Use some of the butter to coat the sides of a 1 1/2 quart gratin dish and arrange the sliced beets and sweet potatoes in a pleasing manner.

Step 2

After all the vegetables have been placed, saute the onions and garlic in the butter until they begin to soften and change color.

Step 3

Stir in the chicken broth and thyme, and season with salt and pepper.

Step 4

Pour the sauce over the beets and sweet potatoes.

Step 5

Cover the dish with foil and bake for about 30 minutes. Remove the foil and continue to cook until the vegetables are tender and brown on the tops. It may take another 30 minutes.

Step 6

Garnish before serving if desired.