Simmer uncovered for 10 minutes, or until beef is tender and sauce is reduced.
Combine and stir to remove lumps.
Add to pan and stir to combine.
Simmer until sauce thickens, about 3 minutes.
Alternatively in H, you can thicken sauce with 0.6 g xanthan gum.
Chef’s notes: this recipe needs to be refined, taking suggestion from Felicity Cloake and considering how to make it thoroughly modernist. Take note of a comment regarding Thomas Keller’s approach, which is just the kind of treatment that a modern recipe requires.
Sear the meat, shallots and mushrooms and keep in the fridge until 2 hours before service. Alternatively, make the dish in entirety as flavours develop and blend overnight in the fridge.