Gather all ingredients. Preheat your oven to 400°F (200°C).

In a large skillet, melt butter over medium heat. Add the onion and sauté until translucent, about 3–4 minutes.

Stir in the flour, salt, and pepper. Cook for 1–2 minutes to form a roux, stirring constantly.

Gradually whisk in the beef broth until the gravy is smooth and starts to thicken.

Add the cubed sirloin steak, carrots, and potatoes. Simmer for 10 minutes until veggies are tender.

Stir in the peas and remove the skillet from heat.

Line a 9-inch pie dish with one pie crust. Pour the beef filling into the crust. Top with the second crust, seal the edges, and cut vents in the top.

Bake for 30–35 minutes until the crust is golden and the filling is bubbly. If the crust browns too fast, tent with foil.

Let the pot pie rest for 10 minutes before serving.