For Roquefort and Pistachio Filling:

1. Bring the Roquefort and cream cheese to room temperature and mash them together thoroughly in a small bowl.

2. Stir in the egg, combine well, and stir in the pistachios.

3. Season with the nutmeg and pepper. The Roquefort is usually so salty that no additional salt is needed.

For Spinach-Feta Filling:

1. Defrost the frozen spinach. Drain it, then squeeze out as much remaining moisture as possible with your hands.

2. Sauté the onion in the olive oil over low heat until tender and golden, about 20 minutes. Add the spinach and cook, stirring constantly, until mixture is dry, 10 to 15 minutes. Season with the nutmeg and salt and pepper, and transfer to a bowl. Cool to room temperature.

3. Stir in the dill or mint, the ricotta, and finally the feta, crumbled into small pieces. Taste and correct the seasoning.

For Rosemany and Prosciutto Filling:

Beat the egg yolks into the ricotta. Stir in the prosciutto, cheese, and rosemary. Season with salt and pepper.

For phyllo triangles:

1. Uncover the dough and remove a sheet. Brush well with melted butter. Sixty triangles will use about ½ pound of butter. Stack a second sheet on top and butter again. Be sure to cover the unused phyllo with the damp towel each time.

2. Cut the buttered phyllo sheets into fifths the short way with a sharp knife.

3. Place a teaspoon of filling in the center of the first strip, about 1 inch from the top. Fold a corner against the filling and then continue to fold, as if you are folding a flag, until the strip is all folded; the filling will expand as it cooks, so do not wrap the triangle too tight. Tuck any excess under.

4. Place the triangle on a buttered baking sheet. Brush the top of the triangle with butter. Continue until you have the desired number of triangles. Filled, unbaked triangles can be refrigerated, covered, for up to 24 hours before baking.

5. Preheat the oven to 350°F.

6. Bake in the upper third of the oven until the triangles are well browned and the filling is bubbling and hot, about 25 minutes. Serve immediately.

7. Completed triangles freeze beautifully and are ready in minutes when you need a quick appetizer. Prepare as above, but place the triangles on an unbuttered baking sheet and omit the final brushing with butter. Freeze them overnight on the baking sheet and then wrap them tightly in clear plastic wrap or in a plastic bag until needed. Do not defrost; they get soggy. Put the frozen triangles on a buttered baking sheet, brush with butter, and bake at 350°F minutes. Serve immediately.