Preheat your oven to 375°F (190°C). Gather your ingredients while the oven warms up.

Heat olive oil and butter in a large pan over medium-high heat. Season sirloin cubes and sear until browned, about 6–8 minutes.

Add the chopped onion and diced carrots. Cook for 4–5 minutes until vegetables are softened.

Sprinkle flour over the mixture and stir for 1–2 minutes to coat everything evenly.

Pour in apple cider and beef broth. Stir well and bring to a boil, then reduce to a simmer for 5–7 minutes.

Transfer to the oven, cover, and bake for 1 to 1½ hours until the meat is tender.

Bring a large pot of salted water to boil. Add peeled and chopped potatoes and cook until fork-tender, about 15 minutes.

Drain the potatoes and return to the pot. Add milk, sour cream, cheddar cheese, and chives. Mash until creamy.

Serve the stew over the creamy mashed potatoes, garnished with additional chives or cheddar cheese.