Remove the outer paper sleeve from the can of condensed milk, submerge the can in a pan of water making sure the water level is above the top of the can. Bring the water to a boil and reduce to a simmer for 3 hours, making sure the water is kept topped up.
Meanwhile, lightly dust your work surface with flour and roll out the shortcrust to a large circle, roughly 1cm thick. Line your tart tin (30cm fluted tin) with the pastry, trim off the edges, and place it back into the fridge to chill for 10 minutes.
Once the pastry has chilled cover the pastry with baking paper and fill with baking beans, then place in the oven for 10 mins. After 15 minutes remove the baking beans and paper and allow to cook for another 5 minutes until the pastry is blind baked and has a chalky feel but pale golden colour. Once removed from the oven brush the pastry with the beaten egg wash, the egg will seal the pastry and ensure it stays crisp after adding the fillings. Allow your pastry case to cool. Once the 3 hours is up with the condensed milk, remove the can from the water and allow to cool at room temperature before opening the can to reveal the dulce de leche caramel, to this stir through the Maldon sea salt.
Next make the frangipane filling. In a stand mixer beat together the butter and sugar until light and fluffy. Then add the eggs one at a time, mixing between each. Finally add the ground almonds and plain flour and beat again until smooth.
Now you can assemble. Spread a thick layer of salted caramel sauce all over the base of the pastry case. Next spoon on the frangipane filling on top and smooth with a palette knife. Peel the pears and then cut in half, use a sharp knife to core them but keep the shape. Then sitting them on a board cut side down, carefully cut horizontal cuts all the way along. Lift the cut pear with the flat of your knife so all the slices stay in shape and lay them in a circular fan around on top of the frangipane, pressing them in gently. Bake the tart in the middle of the oven for 30 minutes, then add scatter over the flaked almonds and return to the oven for a further 10 minutes until the frangipane has puffed up and gone golden. Allow to cool slightly then slice and serve.