Heat 3 tablespoons olive oil in a large frying pan over a medium heat.
Sauté onion, spring onions and garlic until soft and lightly browned.
Stir in spinach and parsley, and continue to sauté until spinach is limp.
Remove from heat and set aside to cool.
In a medium bowl, mix together eggs, ricotta, Glenisk yogurt and feta.
Stir in spinach mixture.
Cover filo stack with 2 overlapping sheets of cling film and then a dampened kitchen towel.
Take 1 filo sheet from stack and arrange on a work surface with the long side nearest you (keeping remaining sheets covered) and brush with some butter.
Top with another filo sheet and brush with more butter.
Cut buttered filo stack crosswise into 6 (roughly 12 x 23/4-inch) strips.
Put a heaped teaspoon of filling into 1 corner of a strip on end nearest you.
Fold corner of filo over to enclose filling and form a triangle
. Continue folding strip (like a flag), maintaining triangle shape.
Put triangle, seam side down, on a large baking sheet and brush top with butter.
Make more triangles in same manner, using all of the filo pastry.
Bake triangles in middle of oven at 1850C for 20-25 minutes until golden brown.