Roll out the pastry on a lightly floured surface and use to line four 10 cm (4 inch) tartlet tins. Prick the bases, line with circles of greaseproof paper and fill with baking beans, then chill for 30 minutes.
Place the tartlets on a baking sheet and bake blind in a preheated oven, 190°C (375°F), Gas Mark 5, for 8 minutes. Remove the paper and beans and bake for a further 2–3 minutes, or until the shells are crisp and beginning to brown. Remove from the oven and set aside until required.
Heat the oil and butter in a pan and fry the red onion until caramelized. Set aside until required. Beat the cream, eggs, salt and pepper together. Add the crushed garlic and chives, and chill the mixture until required.
When ready to serve, divide the onion and the roasted red pepper strips between the pastry shells. Pour over the cream and egg mixture and sprinkle the Munster on top. Cook the tartlets on the middle shelf of a preheated oven, 190°C (375°F), Gas Mark 5, for 20–25 minutes, or until just cooked. Garnish with basil leaves and snipped chives, if liked.