I was there last month fairly early (0700-0900ish, longer than expected because I discovered that my Amex plat got me fast track security - if you don’t have a boarding pass that entitles you to do so, you get one of the staff to take you through; there’s always someone around just after you scan your bp to get through)

Hot food was sausages, reasonably edible scrambled eggs (I’ve had much worse!), and I think the croissants were warm if you got them as soon as they came out. I definitely recall the latter were much better than I expected). The rest was cold cuts and cheese slices, and some lentil salad type thing that actually went pretty well with the sausages. Yogurts, fruit, cereal, etc. too.

They have Leffe Brune on (self-serve) tap, the matching glasses are a sensible 150ml which is just right as it’s dangerously moreish (YMMV, but I’m a fan - and a small one with breakfast works very well!). I don’t recall all of other bottled offerings apart from Belle Vue Kriek (which is also a nice breakfast beer if you’re so inclined;-)

Definitely better than the AMS lounge mentioned upthread. I actually took a flixbus from the AMS area to BRU specifically to avoid dealing with AMS right now. The unexpected bonus of priority security (I was told it was about 40 mins saved by the staffer that helped me; and apparently still a lot better than AMS overall) makes me think I’d be inclined to do BRU over AMS again in the future if circumstances provide the option.

(all of this is for a non-Schengen flight, btw)