• Prep the beef – Sprinkle the beef with salt and pepper.
• Using 1 tablespoon of the oil, brown the beef (in batches if needed) in a large frying pan over medium–high heat for 8–12 minutes. Set aside.
• Prep the onion, garlic and mushrooms – Using the remaining 1 tablespoon of oil, cook the onion and garlic in the same pan over medium heat until softened, 2–3 minutes.
• Add the mushrooms and cook for 2–3 minutes until softened.
• Add the flour and cook, stirring continuously, for 30 seconds (it will form a lumpy paste).
• Cook – Follow either the slow-cooker or stovetop method below.

Slow-cooker method

• Add the sauce ingredients – Add the tomato paste, paprika, Worcestershire sauce and beef stock to the slow-cooker and stir to combine.
• Add beef and mushroom mixture – Add the cooked beef and mushroom mixture and stir gently to combine. The beef may not be completely submerged, which is fine; it will melt into the sauce as it cooks.
• Slow-cook – Cook on high for 4 hours or on low for 8 hours.
• Add the sour cream – Stir in the sour cream for the last 15 minutes of cooking time. The beef should come apart easily with a fork. If not, continue to cook in 15-minute intervals until soft.

Stovetop method

• Return the beef and add the sauce ingredients to pan – Return the beef to the pan and add the tomato paste, paprika, Worcestershire sauce and beef stock.
• Cook, covered – Return to the boil, then simmer over the lowest heat for 1½ hours, covered. Stir occasionally. If the sauce is sticking to the base of the pan, add 125 ml (½ cup) of water.
• Cook, uncovered – Remove the lid and cook for an additional 1 hour to thicken.
• The beef should come apart easily with a fork. If not, continue to cook in 15-minute intervals until soft.
• Add the sour cream – Once the beef is soft and melting, stir through the sour cream to create a thick, creamy sauce.

Assemble and cook pies

• Preheat – Preheat oven to 220°C (425°F) (200°C/400°F fan-forced).
• Prepare the pies – Fill 4 small ovenproof bowls or ramekins with the stroganoff.
• Cut the sheet of puff pastry into four even squares.
• Lay the puff pastry straight on top of the bowls/ramekins and, using your fingers, crimp the pastry around the outside of the bowl.
• Using a pastry brush, brush the tops of the pies with egg and sprinkle with sesame seeds and salt (optional).
• Bake – Bake for 20 minutes or until pastry is golden and flaky.
• Stand and serve – Use oven mitts to remove the pies from the oven. Allow them to stand for 10 minutes before serving.