2) Remove from the heat, drain the sprouts and transfer to an ice bath. Allow to cool completely, then drain. Cut the Brussels sprouts into 0.5cm lengthwise slices and set aside.
3) Add the streaky bacon to a medium saute pan, and cook until just crisp, then remove to a kitchen paper lined plate to drain.
4) Adjust the heat to medium-high, add the onions to the pan and saute until they are translucent and just beginning to caramelise, about five or six minutes.
5) Add the butter to the pan, then add the Brussels sprouts and saute for three to four more minutes. Season with the remaining salt and the pepper.
6) Transfer to a serving bowl or platter and sprinkle with the reserved streaky bacon and the cheese. Serve immediately.