How to Make It
Heat the olive oil in a large saucepan. Add the leeks, celery, carrots and garlic and cook over moderate heat until the vegetables are golden and tender, about 12 minutes. Stir in the squash, kale, tomatoes, beans, chicken broth and rosemary and bring to a boil. Add the bay leaf and cheese rind and season with salt and pepper. Cover and simmer the soup gently until the squash is tender, about 25 minutes. Let cool completely. Remove the cheese rind.
In a food processor, pulse the flour with the rosemary, salt and sugar. Add the butter and cheese and process until the mixture resembles coarse meal. With the machine on, gradually add the ice water and process just until the dough comes together. Divide the pastry into 8 pieces, flatten into disks and wrap in plastic. Refrigerate for at least 1 hour.
On a floured work surface, roll out 1 piece of pastry to a 7-inch round (or 1 inch larger than your bowls). Using a pizza cutter, cut the pastry into 1/2-inch strips. Weave the strips into a lattice; refrigerate until firm. Repeat with the remaining pastry disks.
Preheat the oven to 400°. Ladle the soup into 8 heatproof 2-cup bowls and set them on a large baking sheet. Brush the outer rims of the bowls with the egg wash and top each bowl with a pastry lattice. When the pastry softens slightly, fold the overhang over the rims and press to help the pastry adhere. Lightly brush the lattice tops with egg wash. Bake the pot pies for 15 minutes. Reduce the oven temperature to 350° and bake for about 50 minutes longer, until the pastry is golden brown and the soup is bubbling. Serve hot.