So the Mūlasarvāstivāda-vinaya has a good number of references to festivals occurring at stūpa-s. These seem to have been big thangs with vendors, waived taxes, and so forth. The Chinese monk and pilgrim Fa-hsien collaborates some of this apparently for when visited India. https://twitter.com/BuddhistEthics/status/1341731198641401858

We know that these were popular from at least around the early 1st c. CE (if not earlier). The MSV is probably later as was Fa-hsien of course.

Art at early stūpa sites like Bharhut and Sanchi are replete with celebration with song and dance. We don't see much about food/drink..

but it's definitely implied since NO MONASTICS were involved, so why wouldn't the laity have some food, alchy, gamble (we know this from the literature), and have a nice party?

Even if monastics were involved, many modern Buddhist cultures drink/eat w/ monastics around.

Modern (Protestant?) Western sentiments may feel uneasy at having such celebrations in the "presence" of the Buddha (in the stūpa), but these didn't seem to be an issue long ago at these places.

Some scholars have argued that festivals at stūpas were used to attract patrons. My research suggests this is likely. Another line of theoretical inquiry I work on is just how *prosocial* such festivals and "markets" may have been in terms of fostering collectivity+routinization.

Given the markets existing outside nearly all pilgrimage spots in the Buddhist world that I've experienced as well as at Hindu temple complexes in South Asia, I'd say this is the norm rather than the standard.

A good scholar friend of mine works on premodern food cultures in S. Asia and she might be able to discuss this more.

One piece she's published analyzes inscribed recipes on Hindu temple walls in South India from the 10th-14th centuries. https://www.mdpi.com/2077-1444/9/9/270

Lastly, the very recent edited volume "Buddhist Tourism in Asia" might have some references to modern food cultures around Buddhist temples and the like.

https://www.amazon.com/Buddhist-Tourism-Asia-Contemporary-Buddhism-ebook/dp/B07TXFFSD5/ref=sr_1_1?dchild=1&keywords=buddhism+tourism+in+asia&qid=1608746382&sr=8-1

If anyone has expertise on this it'd be someone in here :)