Bob Armstrong had an honorable career as a public servant and environmental activist. But the Austinite, who died in 2015, is probably most well known these days for his association with the dip at Matt’s El Rancho that bears his name. Bob Armstrong Dip, with its queso, guacamole and seasoned ground beef, is one of the most recognizable dishes in Austin. Now, the restaurant claims Fort Worth restaurant Horseshoe Hill Cowboy Cafe and its owner, Grady Spears, are trying to profit off the dish’s fame. Matt’s El Rancho filed a lawsuit Friday in United States District Court Western District of Texas.

The suit — Matt's El Rancho, Inc. v. Horseshoe Hill Cowboy Cafe, LLC et al — alleges that Horseshoe has engaged in “trademark infringement, unfair competition, trademark dilution, and unjust enrichment.” The trademark for Bob Armstrong Dip, which according to the suit has been around since at least 1986, was filed in 2015.

The complaint also states that counsel for Matt’s El Rancho sent a cease-and-desist letter on March 9, 2018, noting the restaurant’s longstanding trademark rights and its federal registration and requesting that Horseshoe Hill Cowboy Cafe stop using the moniker. Matt’s El Rancho’s owners followed up that letter in June of this year with an email asking the defendant to stop using the trademark, per their previous oral agreement, but Spears did not respond, according to the complaint.

The website for the Horseshoe Hill Cowboy Cafe now lists the appetizer, grossly served in a mason jar style mug, as "Famous Lawsuit Dip." The case has been assigned to judge Robert Pitman. You can read the complaint here.