Using a coffee filter set over a bowl, drain the ricotta. Discard liquid and set ricotta aside.
In a 2-quart saute pan over medium heat, melt butter. Add parsley, creamed spinach, pepper, and nutmeg and cook for 5 minutes. Add ouzo and simmer for another 5 minutes. Remove from heat and stir in ricotta and feta cheeses and the pepperoncini. Let cool and then refrigerate for 20 minutes or more.
Preheat oven to 375 degrees F.
In the meantime, roll out the phyllo dough and, starting from the long side, cut sheets into 2-inch wide strips. Cover with a paper towel and a slightly dampened kitchen towel. Take 3 strips and brush the top sheet lightly with olive oil. Top with 1 teaspoon of filling, placed 1/2-inch above the bottom corner. Fold into a triangle shape and repeat as though folding into a flag. Repeat. Arrange triangles seam side down on a cookie sheet lined with parchment paper. Lightly brush triangles with olive oil and bake for 20 minutes or until golden brown. Cool slightly and transfer to a serving platter. Freeze leftover phyllo dough for other uses.