Pat the steaks dry with a paper towel and season both sides with salt and pepper. Drizzle with one tablespoon of olive oil.
Heat olive oil in a large skillet over medium-high heat. When hot, add the steaks and cook for 1-2 minutes per side for medium-rare.
Transfer the steaks to a plate and loosely cover with foil to rest.
While the steak rests, make the gravy. In the same pan with the remaining juices, reduce the heat to medium.
Add the butter and onions. Cook for 4-5 minutes, stirring, until softened and golden. Slowly pour in the broth, scraping up the brown bits from the pan. Simmer until it reduces.
Stir in the cream and gently simmer for 2-3 minutes, until the gravy is thick and silky. Taste and adjust with salt and pepper.
Serve over the steaks.
Notes
Steaks: Sirloin is best, but rump and roast also work.
Leftovers: Keep in the fridge for up to 4 days or in the freezer for 3 months.