The Great bake off 2: Pies

Signature family pie with flaky topping (rough puff, flaky pastry...)

Apparently rough puff and flaky are the same thing - a quicker way of making puff pastry. The butter is in bits instead of a slab. 

Puff pastry and Viennoiserie dough are different in that Viennoiserie is made with yeasted dough. So you don't really make Danishes with puff pastry, and not with just yeasted dough, but yeasted AND laminated dough. That makes them so flaky and buttery and substantial. Puff pastry is basically just filo dough :-D

I would make cabbage pie with rye puff pastry top. Also, try shaving or grating the butter into the flour. 

Cabbage filling: you need to fry the crap out of the cabbage, to get it as buttery and melting in your mouth as I want it to be. 

Chop cabbage - as much as you need or want. I make this dish with one cabbage head, and then we eat it for as long as there is stew to be eaten :-D It just gets better as one reheats it.
Brown it in butter. Lots of butter. I use about 100 grams of butter for each head of cabbage.
Put the browned cabbage in a dutch oven, with a little bit of butter on the bottom. Pour over bullion, molasses and whole all spice berries. I use about 20 berries for one head of cabbage, 2 bullion cubes (1 per 1/2 liter), about half a cup of water, and 2 tablespoons of molasses. This is a family recipe so everything is approximated and measured in handfuls and squeezes :-D
Fry about 300 grams of minced meat, I use half pork and half beef, and pour over the cabbage. Let stew a couple of hours, until the mixture is practically brown mush. :-D 
Now, for this challenge, I wouldn't be able to let it stew enough, because there's only 2 1/2 hours, and the puff pastry needs to be done, and the pie baked, so I would start with chopping the cabbage and making the puff pastry as the cabbage fries. 

Technical challenge: pork pies

Showstopper: Meringue pie

I think I'd make a lingonberry meringue pie, using lingonberry cordial instead of lemons, but make it like lemon meringue pie. Or maybe use this cranberry meringue pie recipe.

Or maybe make the clear lemon meringue pie :-D

Or maybe try to make a Sans Rival pie - have a nutty pie dough, custard filling, and cashew meringue.