Two Potato Gratin

1 1/2 lbs Yukon gold potatoes, peeled and thinly sliced (Mandolin works great)

1 1/2 lbs sweet potatoes, peeled and thinly sliced

1 pint whipping cream (can also use half and half to skim a few calories)

3 tbs. chopped rosemary, sage, or marjoram (or a combination of all three)

2 cups (packed) shredded Gruyere cheese

1/3 cup Parmesan cheese, finely grated

Salt and pepper

Butter for baking dish

Freshly chopped parsley

Preheat oven to 400 F.

Generously butter 13x9 glass baking dish. Arrange mix of gold and sweet potatoes in bottom of prepared dish, overlapping slightly. Sprinkle generously with salt and pepper. Add herbs into whipping cream, and drizzle 1/4 cup over first layer, followed by a handful of Gruyere. Add another layer of potatoes and repeat above until layers reach 1/2 in. from top of dish. Compress potatoes with hands pushing potatoes down so that they are submerged in the cream. Sprinkle with Parmesan cheese and any remaining Gruyere.

Bake gratin covered 30 min. Reduce oven temperature to 350F. Continue to bake gratin uncovered until potatoes are tender and top is golden brown, about 45 min. Remove from oven; let stand 10 min. Sprinkle with fresh chopped parsley and serve.