Potato-Mushroom Gratin

• 5 tablespoons olive oil
• 2 12 lbs medium russet potatoes, peeled, cut lengthwise into 1/8 inch slices
• 1 12 teaspoons kosher salt
• 34 teaspoon fresh ground black pepper
• 1 14 cups heavy whipping cream
• 1 cup freshly grated parmesan cheese (about 3 oz.)
• 2 tablespoons chopped fresh thyme
• 6 garlic cloves, thinly sliced
• 12 ounces fresh cremini mushrooms, sliced (baby bella)

1. Preheat oven to 375 degrees.
2. Brush 13x9x2" glass or oval ceramic baking dish with 2 tablespoons oil.
3. Arrange 1/2 of potatoes slightly overlapping in dish.
4. Sprinkle with 1/2 teaspoons coarse salt and 1/4 teaspoons pepper.
5. Pour 1/3 cup cream over; sprinkle with 1/4 cup cheese.
6. Repeat layering 1/3 of potatoes, 1/2 tsp salt, 1/4 tsp pepper, 1/3 cup cream, and 1/4 cup cheese 2 more times.
7. Bake uncovered until potatoes are tender, adding additional cream by tablespoons if dry, about 45 minutes.
8. Remove from oven; maintain oven temperature.
9. Sprinkle thyme and garlic slices over gratin.
10. Toss mushrooms in medium bowl with 3 tablespoons oil; sprinkle with coarse salt and pepper.
11. Arrange mushroom slices atop gratin around edge of dish.
12. Drizzle with 1/4 cup of cream; sprinkle with 1/4 cup of cheese.
13. Continue to bake uncovered until mushrooms are tender and potato edges are golden brown, about 20 minutes longer.
14. Can make 1 day ahead.
15. Cool 1 hour in dish; cover and chill.
16. Before serving, cut into 10 pieces.
17. Transfer to rimmed baking sheet.
18. Cover with foil and rewarm in 350 degree over, 10-15 minutes.

olive oil, russet potatoes, kosher salt, fresh ground black pepper, heavy whipping cream, freshly grated parmesan cheese, thyme, garlic, cremini mushrooms

Taken from www.food.com/recipe/potato-mushroom-gratin-347548 (may not work)