Does it specify white or black truffles?
Reading from here:
https://www.gourmetfoodstore.com/preserved-truffles-15180
"They’re also excellent with meats — especially beef and game — or even roasted vegetables. To amplify the flavor, pair them with complementary ingredients like Parmesan, butter, eggs, and mushrooms. You can also pair with subtle ingredients like mashed potatoes or polenta, allowing the truffle to be the star of the dish. For a luxurious touch, drizzle truffle oil or finish with salt.
Common Mistakes to Avoid When Using Preserved Truffles
One of the biggest mistakes is using them straight from the jar without enhancing their flavor. As mentioned, always dry them and lightly sauté to bring out their taste. Another error is overcooking them — preserved truffles should always be added toward the end of the cooking process, as prolonged heat can diminish their already subtle flavors. Also, avoid pairing them with ingredients that are too strong, such as spicy foods or overly acidic dishes, which can overpower the truffles' delicate aroma."
So, knowing all that, and that you want a vegetarian dish, I'd suggest grating them over scalloped potatoes.
Ingredients
3 pounds medium or large russet potatoes (6 medium or 4 large)
2 cloves garlic, finely chopped
1/2 teaspoon fresh thyme leaves (or 1/4 teaspoon dried thyme)
3 1/2 cups half-and-half
2 1/2 teaspoons kosher salt
2 tablespoons unsalted butter, plus more for the baking dish
Instructions
Arrange a rack in the upper third of the oven and heat the oven to 350ºF. Coat a 9x13-inch baking dish with butter.
Prepare the following, adding each to a large pot or Dutch oven (preferably wide) as you complete it: Peel 3 pounds russet potatoes, then cut with a chef’s knife or on a mandoline into thin (1/8-inch) thick slices; 2 finely chopped garlic cloves, and 1/2 teaspoon fresh thyme (or 1/4 teaspoon dried thyme).
Add 3 1/2 cups half-and-half and 2 1/2 teaspoons kosher salt. Bring to a simmer over medium heat, gently folding the potatoes into the sauce every few minutes to bring the potatoes at the bottom to the top, about 13 minutes.
Turn off the heat. Using the slotted spoon, transfer about half of the potatoes into the baking dish and arrange into an even layer. Repeat layering the remaining potatoes, then pour any remaining sauce evenly over the top. Cut 2 tablespoons unsalted butter into 8 pieces and scatter evenly over the top.
Bake uncovered until the potatoes in the center are very tender, and the top is dark golden brown, about 1 hour. Garnish with more fresh thyme leaves if desired. Let cool for 10 minutes before serving.
I wouldn't add the truffles until the very end, 10 minutes tops.
