Mix melted butter with vegetable oil and set aside. This is used for brushing your phyllo sheets.
Make your cheese filling by mixing 1 lb of cottage cheese with 1 cup of sour cream, 1/2 cup of feta cheese, 1 tsp of salt, and 2 eggs.
Take 1 phyllo sheet and brush each phyllo sheet with your oil and butter mixture thoroughly. Fold in your sheet twice along the longer end (into a trifold) and brush again. See video for example.
Place 3-4 tbsp of your cheese mixture at the bottom of the sheet.
Fold your phyllo dough along the edges to form a triangle.
Once each triangle is formed, place it on a greased baking pan or lined with parchment paper. Finish making the rest of your triangles.
Once your pan is ready, brush the tops with the butter mixture.
Place in the oven to bake. Total bake time is 35-40 minutes; however, 20 minutes into baking, take the pastries out and sprinkle them with sparkling water.
Return to the oven to bake for 15-20 more minutes.