Heat oven to 220C/200C fan/gas 7.
Heat a frying pan with a lid over a
medium heat and add the oil. Cook
the leeks, with the lid on, stirring
occasionally until just tender – about
5 mins. Set aside.
On a lightly floured surface, roll out
the pastry and cut out a rough 26cm
circle – use a big dinner plate as a
template. Cover a baking tray with baking
parchment, sprinkle the polenta or
semolina over it, and place the pastry
circle on top. Score a circle about 2cm
from the edge. Spread the leeks out
evenly inside the scored circle, then bake
for 10 mins until the edges have puffed
up. Remove from the oven and turn heat
down to 200C/180C fan/gas 6. Bring
a medium pan of water to the boil.
Blanch the broccoli in the boiling water
for 1 min, then drain and cool under
running water. Drain again and arrange
on top of the leeks. Mix together the
crème fraîche, Parmesan, egg yolks and
some seasoning, then pour evenly over
the veg. Sprinkle with the flaked almonds.
Bake the tart for 15-20 mins until golden.
Serve warm or cold.