In a medium mixing bowl, beat cream cheese and Boursin cheese until smooth and fluffy. Add egg and continue to beat just until incorporated. You don’t want to over beat.
Stir in yogurt, fresh dill, shallots, smoked salmon, grated Gruyere, and white pepper.
Evenly distribute the filling mixture among the 6 tart pans, and carefully spoon on top of the crust. Smooth out with a spatula.
Bake at 350° F for approximately 30-35 minutes, or until the center is barely jiggly and the edges look done.
Remove from oven and cool for at least 15 minutes to allow to set up before serving. Serve warm, cold or at room temperature.