Beef and Beer Potpie

2 T. olive oil
1 lb. boneless chuck roast, cut into 3/4" chunks
1 t. kosher salt
1 t. pepper
6 T. flour, divided
1 1/2 c. chopped leeks
1 c. chopped carrots
2 T. choppped fresh thyme (or 2 t. dried)
1/2 c. stout beer (like Guiness)
2 1/2 c. beef broth
1 c. chopped butternut squash
1/2 pkg. puff pastry]
1 egg, slightly beaten
1  T. water

1. Preheat oven to 425°F. Heat the oil in 
a 10-inch cast-iron skillet over medium-high. Toss together the beef, salt, pepper, and 2 tablespoons of the flour in a medium bowl. Add to skillet; cook, stirring often, until the pieces are browned on all sides, about 8 minutes. Add the leeks, carrots, and 1½ tablespoons of the thyme. Cook until the vegetables begin to soften, about 4 minutes. Add the beer; cook 1 minute, stirring to loosen any browned bits from the bottom of the skillet. Whisk together the stock and the remaining flour; add to the skillet and bring to a 
simmer, stirring frequently. Reduce heat to medium; cook, stirring occasionally, until the beef is tender and the sauce thickens, 30 to 35 minutes, adding the squash after 15 minutes.
2. Roll out the puff pastry gently into a 12-inch square. Place the pastry over 
the simmering beef mixture. Whisk together the egg and water; brush over the pastry. Cut several slits in the center of the pastry. Bake in oven until the 
pastry is golden brown, about 15 minutes.