570 g beef strip steak, trimmed and cut into 1-inch cubes
7.5 tsp coarsely cracked black pepper, divided, plus more for garnish
8.5 tsp kosher salt, divided
15 ml neutral cooking oil (such as canola oil)
70 g unsalted butter, divided
120 ml finely chopped shallots (from 2 large shallots)
1.5 tbsp drained green peppercorns in brine (optional)
5 g finely chopped fresh thyme leaves, plus more for garnish
60 ml cognac or brandy
120 ml unsalted beef or chicken stock
240 ml crème fraîche
5 g Dijon mustard
25 g finely grated Parmigiano-Reggiano cheese
Instructions
Bring a large pot of salted water to boil over high. Cook pasta according to package directions for al dente. Drain pasta, reserving 120 ml cooking water; set aside.
Meanwhile, pat steak dry with paper towels, and sprinkle with 2.5 tsp of the black pepper and 1.25 tsp of the salt, pressing gently for the pepper to adhere to the steak.
Heat oil and 15 ml of the butter in a large skillet over medium-high. Add half of the steak pieces to the skillet, keeping space between each piece. Cook, undisturbed, until browned and crispy on bottoms, about 1 minute.
Flip steak pieces, and continue cooking until browned on other side, about 1 minute. Flip pieces again, and cook, turning occasionally, until most sides are browned and crispy and steak is almost medium-rare, 1 to 2 minutes.
Transfer steak to a large bowl. Repeat cooking process with remaining steak pieces, transferring cooked steak to bowl with the first batch; set aside. Do not wipe the skillet clean.
Reduce heat to medium, and add shallots, green peppercorns, and thyme to drippings in skillet. Cook, stirring often, until shallots are softened, about 2 minutes.
Remove skillet from heat, and pour in cognac to deglaze skillet. Return skillet to medium, and cook, stirring constantly to scrape up any browned bits on the bottom of the skillet, until cognac is nearly evaporated, about 30 seconds.
Pour in broth, and bring to a simmer over medium. Simmer, stirring occasionally, until slightly reduced, about 2 minutes.
Stir in the remaining 55 g butter, 15 ml at a time, until sauce is glossy and smooth, about 2 minutes.
Stir in crème fraîche, Dijon mustard, remaining 2.5 tsp black pepper and 0.25 tsp salt. Simmer, stirring occasionally, until sauce is slightly thickened, about 5 minutes.
Add drained pasta, Parmigiano-Reggiano, and 120 ml of the reserved cooking water to sauce, and toss to coat.
Add additional cooking water as needed, tossing constantly, to create a glossy sauce. Remove from heat, and toss in steak cubes.
Divide pasta and steak evenly among 4 plates, and garnish with additional fresh thyme and black pepper.