Preheat oven to 325 degrees F. Butter 9" springform pan.
Mix bread crumbs, 1/4 cup gruyere and 1 teaspoon minced dill and sprinkle into buttered springform pan to coat sides and bottom. Refrigerate.
Melt butter in skillet over low heat. Add shallots, and cover and cook until translucent (about 10 minutes), stirring occasionally.
Mix cream cheese in food processor until smooth, add eggs, cheese, 1/2 & 1/2, dill and salt. Pulse until mixed. Add salmon and shallots and pulse again. Filling should retain some texture.
Pour into prepared pan. Set pan in roasting pan. Add enough hot water to roasting pan to come half way up sides of springform pan. Bake 1 hour and 20 minutes at 325 degrees F. Turn off oven and cool cheesecake in oven with the door ajar for another hour. Transfer to rack and cool to room temperature. Refrigerate for up to two days. Can be cut into smaller portions and frozen for up to a month. Bring to room temperature before serving.