Possible Toppings: sour cream, green onions, chives.
Preheat oven to 450 F. Line a large baking sheet with parchment paper.
Bring a large pot of water to a boil. Boil perogies and stir occasionally for 5 mins. Drain and place in a large bowl. Toss perogies with olive oil and place on baking sheet. Sprinkle with feta and oregano.
Bake for 8-10 mins until feta has lightly browned.
In a medium bowl, add all the tzatziki ingredients and mix well. Serve with perogies.