ready rolled all butter puff pastry rectangles (2 packs) • Gruyere cheese, grated • Greek feta, crumbled • pitted green olives, cut it half • spring onion (100 g), finely sliced • parsley, finely chopped • mint leaves, finely chopped • large potatoes, peeled, washed and very thinly sliced on a mandolin (540 g) • large eggs plus 1 large yolk • double cream • creme fraiche • sesame seeds •