Preheat the oven to 350 degrees F.

Finely grind nuts with a food processor.

Add flour and sugar and pulse food processor again to combine the ingredients.

Cube the butter and add it to the nut mixture in the food processor.

Pulse the food processor until you have a mixture that resembles cookie dough and the butter is fully mixed in with the nuts and flour.

Empty the dough into a 10" tart plate or a regular deep dish pie plate. Press the dough with your fingers into the tart plate. This will take a few minutes to get it even over the bottom of the tart plate and up the sides.

Once the crust is pressed into the plate, set it aside while you make the filling.

Wash and chop the rhubarb into about a 1/4" thick pieces. Spread the chopped rhubarb in the tart plate.

Whisk the whole egg and egg yolks with the corn starch until the corn starch is well mixed.

Whisk in the honey, sugar, vanilla and cream.

Pour custard over the rhubarb and put the tart in the oven.

Bake for 50 minutes or until the custard set and doesn't move when you jiggle the tart dish.

If it is runny in the centre, put it back in the oven for 3-4 minutes at a time and check it often. It will set quickly.

Let the tart cool for at least an hour before slicing.