Mushroom Gruyere Grilled Cheese

Truffle Spread:

1/2 cup robiola fresca cheese, at room temperature (substitute cream cheese if unavailable)

1/2 tablespoon lemon zest 

1 teaspoon chopped fresh rosemary 

1/2 teaspoon white truffle oil 

Salt and freshly ground black pepper 

Pan-Roasted Mushrooms:

6 tablespoons extra-virgin olive oil

2 pounds mixed wild and cultivated mushrooms, trimmed and thickly sliced 

Kosher salt and freshly ground black pepper 

2 shallots, finely chopped 

2 cloves garlic, finely chopped 

2 tablespoons unsalted butter 

2 tablespoons chopped fresh rosemary 

2 tablespoons fresh thyme leaves 

Mushroom Gruyere Grilled Cheese:

4 slices pan de mie or French Pullman bread, cut 3/4-inch thick

1 stick (8 tablespoons) European-style butter, at room temperature

4 thin slices Gruyere

4 thin slices fontina

4 tablespoons chopped fresh herbs (parsley, tarragon, chives and chervil) 

Coarse sea salt