The Simpsons has paid tribute to Rick and Morty in a previous opening couch gag (see below), and producer Al Jean has tweeted that they're poised to give another nod to the show, and to Rick's favorite sauce. Rick has made no secret of his affection for McDonald's limited edition Szechuan Sauce for Chicken McNuggets, originally released in 1998 as a promotional tie-in for Disney's Mulan and recently re-released in a disastrous attempt at satisfying Rick and Morty's occasionally crazy fan base.
Eagle-eyed fans will recognize the label, and one fan actually already did, and asked Jean for confirmation. Jean has confirmed: it's the sauce. Apparently, the Simpsons production and writing crew are big R&M fans.
yes a little shout out to R&M— Al Jean (@AlJean) November 2, 2017
And that's the way the news goes.