- 20 minutes
- 35 minutes
- Preheat oven to 325. Coat a large casserole dish or 6 individual ramekins with cooking spray.
- Peel potatoes and slice or mandoline to 1/4" thickness. Arrange potatoes in a single layer in prepared dish or ramekins. Arrange shrimp in a single layer atop potatoes.
- In a large bowl, combine breadcrumbs, salt, pepper, and fresh herbs. Melt 2 tbsp. butter and pour over crumbs, stirring to evenly coat all of the breadcrumbs with butter. (This step might seem superfluous, but it really helps the gratin to brown beautifully and evenly.)
- In a saucepan, melt remaining butter. Add shallots and garlic and cook until very aromatic, about 3 minutes. Add half and half and bring to a boil. Once boiling, reduce to a simmer and stir. Add grated parmesan and stir constantly over a low simmer until cheese is melted and sauce is very thick.
- Pour hot sauce evenly over potatoes and shrimp. Cover with breadcrumb mixture and bake 20-25 minutes, until topping has browned and potatoes are easily pierced with a fork. Let stand 5 minutes before serving.