Put the flour and salt in a food processor and pulse to mix. Add the butter and pulse again until the mixture resembles coarse breadcrumbs.
Add the poppy seeds and water, and pulse again until the dough barely starts to come together.
Turn it out onto a lightly floured surface and knead into a ball. Flatten it, wrap it in plastic wrap, and refrigerate for 30 minutes.

Roll out the dough on a lightly floured surface and line a 9″ x 2″ (23cm x 5cm) round mold with it.
Prick the bottom with a fork and refrigerate for 30 minutes.

Preheat the oven to 400°F (200°C).

Place the mold on a baking sheet and line it with parchment paper.
Fill the mold with dried beans.
Bake for 20 minutes, then remove the parchment paper and the beans, and bake for 5 more minutes.
Remove the cooked dough from the oven.

Reduce the oven temperature to 350°F (180°C)

Prepare the filling while the dough is baking.
Place the carrots in a steamer and cook for about 7 minutes, or until tender. Set aside.

Melt the butter in a pan over medium heat, add the onions, salt, and pepper.
Add the cumin and cook the onions, stirring, until they are softened, without browning (about 15 minutes). Beat the eggs and cream, and season with salt and pepper.

Place the onions and carrots in the bottom of the baked dough, sprinkle with poppy seeds, and pour the egg mixture over the top.
Sprinkle the cheese on top and bake for 20 to 30 minutes, or until the filling is set and a toothpick inserted into the center comes out clean.