First make the pastry. Add the flour, sugar and butter to a food processor or electric mixer and mix until fine crumbs.
Add the egg yolks and mix until a smooth soft dough, adding a little water as needed.
Knead pastry lightly on a floured surface then cut into 8 pieces and roll out each piece until a little larger than a 3 1/2 inch loose based tart tin.
Lift the pastry into the tin and press up the sides then trim a little above the top of the tin to allow for shrinkage.
Continue until you have lined 8 tins. Prick the bases with a fork, put tins on a baking sheet and chill for 15 minutes, longer if time.
Preheat the oven to 350 degrees. Line each tart with a square of parchment and fill with baking beans or dried pulses.
Bake for 10 minutes, remove the paper and beans and cook for 4-5 minutes until the bases are crisp.
While the tarts cook, mix the egg yolks and whole egg with the sugar in a bowl.
Bring the milk and cream just to the boil in a saucepan then gradually whisk into the yolks.
Add the vanilla essence then strain back into the pan.
Add the rhubarb to a small roasting tin, dot with the butter and sprinkle with the sugar.
Take the tarts out of the oven, reduce the temperature to 325 degrees.
Pour the custard mixture into the tart cases put in the oven with the rhubarb on the shelf above. Bake the tarts for 15-20 minutes until just set with a very slight wobble to the centre and the rhubarb for 20-25 minutes until just tender and still bright pink.
When the rhubarb is done, add the redcurrant jelly to the rhubarb juices and stir until melted. Leave to cool.
To serve, take the tarts out of the tins and put on serving plates. Mix the strawberries with the rhubarb and spoon over the tops of the tarts.