Preheat oven at 350°.
Stack 4 sheets of phyllo, one on top of the other.
Using a sharp knife cut dough in half, creating a long rectangular shape.
Brush the bottom of a baking sheet with olive oil.
Place the first phyllo dough on the baking sheet and brush lightly all the edges and all over with olive oil.
Place the second phyllo on top of the first and repeat until all 4 sheets of phyllo are well brushed and neatly stack.
Using a long knife cut the dough into 4 to 6 portions.
Bake only the phyllo dough, until golden brown, about 2-3 minutes.
Remove phyllo from the oven and gently transfer it on a serving platter.
In a separate bowl, mix together the feta cheese, yogurt, vinegar and season to taste with salt and pepper.
Spread baby spinach on top of the crispy phyllo followed by diced tomatoes, onions and olives.
Drizzle feta yogurt dressing all over and garnish with chopped parsley.
Serve immediately.