Preheat oven to 350º F.
Saute onions and garlic in EVOO in a large saute pan over medium heat. When onions and garlic start to cook, after about 5 minutes, add spinach and mushrooms. Allow mixture to cook thoroughly. Add salt and pepper to taste and put mixture into a large mixing bowl.
While mixture is still warm, add cream cheese, feta cheese, bread crumbs and dill. Mix thoroughly. Mixture should not be loose-if it is, add more bread crumbs.
Take one sheet of filo dough and either spray EVOO evenly over it or brush about a teaspoon with a pastry brush. Add another layer of dough and repeat with more EVOO until you have four sheets. Add 1/4 of the filling to the dough 2 inches from one end and spread it out so it is 1 inch from each width end.
Fold the width ends over the filling and then start rolling the dough from the end closest to the filling until it is completely rolled up and the end is tucked under the bottom of the roll so it looks like a burrito or an egg roll.
Repeat with the other filo leaves and place your strudels on a cookie sheet. Bake for 1/2 hour. Allow strudels to cool slightly before serving. Give each person one strudel with a simple green side salad or a Greek salad.