Blend sundried tomatoes, olives, oregano, garlic, olive oil, salt, and pepper in a food processor until finely chopped and spreadable. Adjust seasonings. Set aside.
Heat oven to 350 degrees.
Roll out puffed pastry into a 12-inch circle on parchment paper. Spread filling on one pastry round. Top with the second round. Cut into strips emanating from the center to make a sun-ray pattern. Brush with egg wash, sprinkle seeds, and bake for 30-35 minutes.
Blend feta, cream cheese, olive oil, lemon juice, salt, and pepper in a blender or food processor until smooth. Adjust seasonings. Serve as a dip with the baked tart.
