I made this a few more times and discovered that it's not as sensitive as I thought so I tweaked the recipe. Enjoy!

1/2 cup vegetable oil
2 large onions, chopped
20 ounces frozen chopped spinach, thawed
2 tbsp chopped fresh dill or 1 tbsp dried dill
2 tbsp flour
10 ounces feta cheese, crumbled
4 eggs, lightly beaten
kosher salt and freshly ground pepper to taste
1 1/2 to two packages phyllo (filo) thawed
2/3 pounds unsalted butter, melted

1. Preheat oven to 350 degrees F (175 degrees C).

2. Squeeze about half of the liquid out of the thawed spinach. Reserve liquid.

3. Heat vegetable oil in a large saucepan over medium heat. Slowly cook onions until tender.

4. Add spinach, dill and flour and stir together. Cook for 10 minutes. If spinach begins to stick to the bottom of the pan, add liquid from the spinach.

5. Remove from heat, add feta, eggs, salt and pepper. Place mixture in bowl. If necessary, drain.

6. Unwrap the phyllo on a cookie sheet, keeping the stack covered with plastic when not peeling off a sheet. Place one sheet of phyllo on a cutting board. Brush with melted butter. Place a second sheet on top of the first and press together. Using a pizza cutter or similar device, cut into three strips lengthwise. Place a dollop of the spinach mixture in the center of on end of each strip, leaving phyllo exposed on all edges. Fold the end corner over to the opposite edge to form a triangle. Flip the triangle over, matching the edges until you reach the end of the strip. The mixture should be enclosed entirely in the triangle.

7. Place on a lightly greased cookie sheet and brush the top with melted butter. Repeat until all filling is used. If liquid forms at the bottom of the bowl, drain it off or squeeze it out.

8. Bake until golden brown, approximately 20 to 25 minutes.

Tip: A lot of recipes call for squeezing all of the liquid out of the spinach and just cooking the filling until what moisture is left is gone. I don't like this. It really does take a good 10 minutes or even more to meld the flavors and, while you don't want to put liquid in the triangles, it's best if the filling isn't dry. I also put in more feta than most and skimp a bit on the salt.