To celebrate the the Nativity of Mary, Catholic folks of The Great Mangaloid Race (TM) celebrate the Monti Fest around this time of the year. Given the dearth of available scholarly studies of this phenomenon, I can only recount from observation.
The Monti Fest is technically celebrated in honor of said Nativity, but given that Onam, the Keralite Hindu harvest festival, is also technically a celebration of the legendary hero Mahabali, I'm inclined to think of it likewise as a harvest festival with a cultural tint.
Having not actually attended one of these in years due to my studies and travels abroad, this is my first Monti Fest in recent memory. Food served is to be all vegetarian (it is, after all, a harvest festival), and apparently the number of dishes has to be odd (1,3,5,7, etc). This year, instead of the parental generation preparing tradition dishes, we young 'uns cooked up some relatively exotic fare (with one preparation of dal, or thick lentil stew). Specifically, garlic-butter baby carrots, vegetable lasagna, cashew gravy and potato stuffed into bell peppers, vegetable kofta manchurian, mixed vegetable stir-fry, and a salad. I helped ... a little. At any rate, this unconventional spread for a traditional feast got fairly glowing reviews from the elders of all three families, much to our satisfaction.
EDIT: Apparently there is some more information about the origins of this feast: http://www.daijiworld.com/chan/exclusive_arch.asp?ex_id=129