These guys have such a bad rep although I do think they're coming into their own theses days.
My late husband wouldn't touch them but I suspect that was because his mother, who was not much of a cook, had boiled the crap out of them
I cam across Ina Garten's Brussels Sprouts Gratin recipe recently and it's on the menu for this week.
ATK has a similar recipe that uses gruyere and shallots....I may try that.