Cheesy Root Vegetable Gratin

Directions

1. 1

   Grease baking dish with butter.

2. 2

   Slice sweet potato, gold potato and purple potato into very thin rounds (using a mandoline is easiest).

3. 3

   The aluminum foil should be tightly wrapped around the baking dish to allow the dish to steam a little and for the vegetables to get tender before uncovering it.

4. 4

   Keeping the slices as uniform in thickness as possible will greatly help even cooking throughout the gratin.

5. 5

   Using a mandoline will not only ensure even thickness, but will also reduce the prep time. If you don’t have a mandoline a very sharp knife is the next best thing I recommend

6. 6

   Covering this dish in the beginning will allow the vegetables to soften without drying the dish out. Once the vegetables get to a good point, uncovering them will allow the top of the gratin brown and crisp up, while allowing some of the excess liquid to thicken/evaporate.

7. 7

   This dish can be made up to a day ahead of time and refrigerated, tightly wrapped in foil. When ready to bake, just place the covered gratin in the oven, adding about an extra 5-7 minutes of baking time to the dish (covered).

8. 8

   Preheat oven to 400˚F (205 C). Cover with foil and bake for 30 minutes or until vegetables are soft. Uncover gratin and top with shredded gruyere (optional). Place gratin back into oven, uncovered, and continue to bake for an additional 18 to 20 minutes or until vegetables are fork tender, cheese has melted and the top has lightly browned.