01 -
Preheat oven to 375°F. Heat butter and olive oil in a pan over medium-high heat.
02 -
Season sirloin cubes with salt and pepper. Add to the hot oil in the pan and toss to brown on all sides, about 6-8 minutes.
03 -
Add chopped onion and chopped carrots to the pan. Cook with the beef for 4-5 minutes.
04 -
Sprinkle the mixture with flour and stir to combine and coat. Heat for 1-2 minutes. Add apple cider and beef broth, stirring to mix, and bring to a boil.
05 -
Transfer mixture to an oven-safe pan, cover, and cook in the oven for 1 to 1 1/2 hours.
06 -
Meanwhile, cook potatoes in boiling water until tender. Drain and return to the pan. Mash together with milk, sour cream, shredded cheese, and chives until smooth.
07 -
Serve the beef stew hot over the creamy mashed potatoes.