Mung bean chili?
Are you thinking of a beef chili with mung beans instead of kidney's or pintos, or a vegetarian one?
What would be distinctive about mung beans in this use? I'm more familiar with their use as sprouts and cellophane noodles. I can imagine making 'ants climb a tree' with ground beef instead of pork, and chili seasonings instead of the more Chinese ones. It would almost be variation on Cincinnati chili.
I never noticed mung beans to have a noticeably sweet flavor. If anything, I always considered them a bland starch. I grew up eating them stewed with beef, which I think brings out some undesirable mineral flavors in both the beef and beans. I much prefer them cooked with pork or shellfish.