Filo pastry is sold in two packages. Open one, leaving the other closed to prevent drying. Using a pastry brush or soup spoon, butter a sheet pan before lying filo evenly to cover (this will require 3 to 4 individual sheets of pastry). Butter every other layer of filo pastry until all the sheets have been used, focusing on the edges to keep them hydrated. Avoid heavy, thick puddles of butter, which can make the pastry soggy.
Once the bottom layer of the pita has been prepared, preheat oven to 350°. Heat oil in a frying pan over medium heat. Sauté green onions until softened, then set aside to cool.
Crack the eggs into a large bowl and whisk until fluffy. Add cottage cheese, feta, sautéed green onions, spinach, and dill, tossing with your hands to combine. Pour mixture into the bottom layer of the pita, spreading to distribute to all corners. Using the same buttering technique, layer the second package of filo pastry over the filling.
Roll the top and bottom edges of the pastry together, tucking it under itself all around edge of pan. Bake for 50 minutes or until crust easily holds together when lifted up from baking pan with spatula. Cool, then cut into triangles and serve at room temperature.