To use frozen summer truffles, remove just as many as you need from the freezer, and allow them to slowly partially thaw, just until they can be cut or sliced. Use a sharp knife to cut them into pieces or a truffle slicer to shave them. Gently warm the sliced/cut truffles to awaken their full flavor & aroma by sautéing them or heating them in oil, then add them to your food.
In terms of recipes, these truffles can be used in any dish calling for fresh summer truffles. Classic pairings include risotto (risotto tutorial), fine cheeses (especially parmigiano reggiano), poultry, potatoes, and roasted meats.
Note: Any unused truffles that have more than slightly thawed can be stored in the refrigerator for up to two days, but should not be refrozen.