The Coffee Bean and Tea Leaf has a drink they call a Moroccan Mint Latte. It’s a tea latte with chocolate. You can get a fairly good approximation by making hot chocolate using mint tea instead of hot water. Katie suggested Bigelow Plantation Mint (after I mentioned that I’d tried it with Stash Moroccan Mint), which seems to work well.
Update: I forgot to mention the key difference between the two varieties of tea that I tried. Black tea works better with chocolate than green tea.