Puff Pastry Roast Beef Pot Pies

Preheat oven to 350 degrees F (175 degrees C).

Heat olive oil in a large stockpot over medium heat; cook and stir stew meat until browned, 2 to 3 minutes. Add onion; cook and stir until onion is lightly browned, 3 to 4 minutes. Add potatoes, carrots, celery, and garlic; cook and stir until slightly tender, 3 to 4 minutes.

Stir flour, butter, bay leaf, salt, and pepper into stew meat mixture; cook and stir until flour is dissolved and a gravy is forming, about 2 minutes. Pour beef stock over meat mixture, scraping brown bits of food off the bottom with a wooden spoon; cook until gravy begins to thicken, about 5 minutes.

Mix milk and rosemary into stew meat-gravy mixture; continue cooking over low heat for 15 to 20 minutes. Stir peas into mixture.

Pour stew meat-gravy mixture into individual pot pie pans or a 12-inch cast iron skillet; top with puff pastry, crimping the sides of the pastry down tightly. Cover with aluminum foil.

Bake in the preheated oven until pastry is puffed and golden, 30 to 45 minutes.