Heat 1 tsp oil in a frying pan over a high heat. Fry 1 finely sliced shallot and ½ finely sliced and deseeded red pepper until soft. Take off heat and stir in a few pitted and finely chopped olives, a small crushed garlic clove, a small handful of finely chopped parsley and some seasoning. Cool the mixture completely.
Preheat oven to 200°C. Roll out 150g puff pastry into a 16cm square and place on a baking sheet. Arrange pepper mixture in a line towards you down the middle third of the pastry. With a sharp knife, cut 1cm-wide slits, running from 2cm away from the pepper mixture to the edges of the pastry, slanting the slits towards you. Brush the pastry with some beaten egg. Fold the pastry ends over the filling, then, starting at the end furthest from you, fold the pastry strips over the pepper mixture to give a plait effect. Brush the top of the pastry with more beaten egg and sprinkle with sesame or poppy seeds. Cook in the oven for 25 minutes until golden and crisp. Serve immediately. (Also tastes great served at room temperature.)