In a large mixing bowl, combine butter, sugar, almonds, salt, and 2 Tbsp flour using a pastry scraper.
When the mixture is well combined, add the remaining flour, egg yolk, and olive oil. Mix again with scraper until it forms a smooth ball.
With your fingers, press the dough as evenly as possible into a tart pan with removable bottom. Press the dough above the sides of the pan and cut off excess with rolling pin (roll it across the top).
Bake the pastry in a 425 degree oven until lightly browned ~ 10 minutes.
Make the filling: in a saucepan, whisk together all of the ingredients forth filling except the butter and olive oil. Cook over medium heat, whisking constantly to lighten the mixture, until thickened.
Off the heat, add the butter in pieces and whisk until melted. Add the olive oil and whisk until combined.
Pour the filling into the cooled crust and place in refrigerator to set for at least one hour.