In a large soup pot, heat the olive oil until shimmering, then add the beef cubes. Sear on all sides until golden brown, about 1-2 minutes. Do not cook the beef through, only sear it. Remove from the pot and set aside.
Using the oil and grease in the pan, sauté the onions until tender, then add the frozen vegetables. Stir in the veggies until mostly thawed, then add the celery, peppers, and garlic. Pour in the beer, sriracha, and Worcestershire sauce, and simmer until the liquid has reduced by half, about ten minutes. Season with salt and pepper.
Pour in the beef broth, lemon juice, paprika, and brown sugar. Stir until combined and boiling, then reduce the heat and simmer for another ten minutes.
Preheat the oven to 375°F while the soup simmers. In a small bowl, whisk together the egg with some water. Arrange the seared beef into individual ramekins. Use a ladle to spoon the stew over the meat until the ramekins are filled.
Quickly cover each ramekin with a quarter of the puff pastry. Brush with the egg wash. Pop into the oven and bake for 10-15 minutes, until the pastry is puffed and golden. Let cool for 10-20 minutes before serving as the ramekins will be HOT. Enjoy!