Heat your oven to 425°F. Toss the asparagus with olive oil, salt, and pepper. Roast for 12 to 15 minutes until tender with crispy tips. Finish with lemon.
Pat the steaks dry and season well. Heat a heavy skillet over high heat with olive oil and don't touch the steaks once they hit the pan — 3 to 4 minutes per side until deeply browned.
Lower the heat slightly, add the butter, garlic, and herbs, and spoon the butter over the steak. Remove and let rest.
Same pan, medium heat: add butter, then mushrooms. Don't stir for a few minutes; let them get dark and a little crispy.
Add the shallot and garlic, cook briefly, then deglaze with beef broth, scraping up the browned bits. Add the cream and Dijon, simmer until thick enough to coat a spoon, and season to taste.
Slice the steak, spoon the mushroom sauce over everything, and serve with the asparagus.