Roll the pastry out thinly and line eight 9cm tartlet tins. Rest for half an hour, then prick the bases with a fork, line with greaseproof paper or cling film and weigh down with baking beans. Bake at 180C/350F/Gas Mark 4 for 12 minutes, then remove beans and paper or clingfilm and return to the oven to dry out for a further 7-10 minutes. Cool.
Heat the butter gently with the sugar in a pan large enough to take all the filling ingredients. Stir constantly, and bring up to the boil. Add the cream, and the flour and beat well until evenly mixed. Stir in the nuts and bring back up to the boil. Spoon immediately into the pastry cases and return to the oven for 10 minutes.
Leave to cool and serve warm or at room temperature with whipped cream or vanilla icecream.