Your timing is impeccable! Since the closure of the much-mourned Commander's Palace, which offered 25-cent martinis at lunchtime, as well as a daily Champagne Brunch, Las Vegas has not offered that venerable institution on weekdays at any property. Whether your question somehow affected things and you wished this into being, we couldn't say, but in the space of the past week, two major Strip properties have substituted brunch for breakfast and lunch buffets, with one offering champagne daily.
It was earlier this week that Monte Carlo announced that its buffet would now be serving brunch daily from 7 a.m. to 3 p.m., with a menu featuring made-to-order omelettes, chicken fried steak, Eggs Benedict, Mahi Mahi, jambalaya, baked Ham, Mongolian beef, and fresh pastries and desserts on weekdays for $15.99.
Champagne is only offered Friday through Sunday, when a specialty Seafood Brunch is served in addition to the regular fare, featuring crab legs, shrimp, sushi, and oysters (based on market availability), for an optional $4 upgrade. For an additional $2, guests may order unlimited champagne or mimosas during the Seafood Brunch, so you could at least enjoy a Friday Champagne Brunch on June 3, if not a Tuesday one on 31st.
All is not lost, however, since The Cosmopolitan has also just introduced daily brunch to The Wicked Spoon, recently named Best Buffet in Las Vegas in USA Today, as picked by a panel of experts that included our own Anthony Curtis. During the week, for $22 you can enjoy the brunch spread, plus one glass of champagne (actually Italian sparkling wine), a mimosa, or a Bloody Mary. On the weekend (Saturday and Sunday only), booze-free brunch is $29, or for $37 you can enjoy bottomless drinks.