Heat two tablespoons of olive oil in a large pot or large dutch oven. Coat cubed steak in flour and sear on all sides in the oil, in small batches.

Remove beef from the pan and set aside.

Dice onion and mince garlic cloves, and cut large mushrooms in half. Add a little more oil to coat the pot, and sauté diced onion, garlic, and mushrooms until the water comes out of the mushrooms and reduces; about 15 min.

Add in the brown sugar, Worcestershire sauce, thyme and salt and pepper. Pour in the beef broth and Guinness, and add back the browned beef cubes. Bring to a boil, and then simmer on low for about an hour to an hour and half on the stove top.

At this point you can put it in the fridge overnight, or top with pastry and bake.

To make the pie, put the stew mixture into a pie plate, baking dish, or individual ramekins, and the thawed puff pastry lid to the top of the filling. Bake at 400 for about 25-30 minutes, until the pastry is golden brown.