On a work surface, generously season beef with salt. Using a smoking gun, cold smoke beef 12 minutes. Transfer to a freezer-safe container or bag, then freeze overnight. The next day, using a meat slicer, thinly slice beef, then finely dice. Transfer to an airtight container and refrigerate.

Heat the water bath of an immersion circulator to 140°F. In a vacuum bag, combine all ingredients for the Pecorino Romano-Infused Olive Oil. Seal and cook sous vide 2 hours. Strain and transfer to an airtight container. Reserve.

In a pan over medium flame, heat butter for the Pecorino Romano Mousse. Add onion and cook until soft and translucent. Deglaze pan with wine and continue to cook until liquid has reduced. Add cream, Pecorino Romano PDO, and sachet. Bring mixture to a simmer, stirring constantly. Remove from heat and let cool 5 minutes. Remove sachet and transfer to a blender. Purée until smooth, then pass through chinois. Let cool, then whip by hand or with a stand mixer until medium peaks form. Transfer to an airtight container and refrigerate.

Heat oven to 325°F. On a work surface, brush focaccia slices with beef fat. Transfer to a sheet pan and press down to flatten. Bake until golden brown. Season with salt, then let cool to room temperature.

In a small mixing bowl, combine 175 grams Beef Tartare. Fold in desired amount pickled tomato, shallot, parsley, and chives. Drizzle with Pecorino Romano-Infused Olive Oil and toss to coat. Season with salt, black pepper, and reserved tomato pickling liquid. Set aside.

On a cold serving plate, place 2 ounces Pecorino Romano Mousse. Top with Beef Tartare mixture. Finish with Pecorino Romano PDO and crumbled Focaccia Chip.