The opening shot of a Great Menu War may have been fired yesterday when a Maryland restaurateur contended in court that he had a beef with a D.C. restaurateur.

Sandwiched in between other suits filed yesterday in federal court here was a claim by Roy Passin, owner of "Roy's Place" in Gaithersburg and "Roy's Place Too" in Columbia, that a former employee of his had taken Passin's recipes, menus, sandwich names and other restaurant know-how to "Dudley P's," a pizzeria-restaurant at 21st and M Streets NW.

Passin asserted that he has a reputation of being a "sandwich inventor and engineer of distinction" whose ideas for unusual sandwich combinations are protected under the law, and that the alleged use of those combinations by another company had eaten into his profits.

Rich Bake, vice president of Dudley P's, said he was unaware of the suit until he was contacted by a reporter, but that on the face of it he felt it was a "little absurd."

"How can you hold an yright to a food product? How can you say a Reuben sandwich is their idea? If a business can do this (file suit), why hasn't McDonald's put Burger King and Burger Chef out of business?" Baker said.

Baker confirmed that he had hired Roy Passin's former manager, Thomas Dickinson, after Dickinson had been discharged by Passin earlier this year. However, he said he hired Dickinson only because he "needed a good man" to help him change his restaurant menu to include more sandwiches and not in any attempt to steal sandwich ideas.

"The man (Dickinson) has earned his livelihood in the restaurant business almost all his life. They should have expected him to remain in the restaurant business," Baker said.

Dickinson, who Baker said is in the hospital with a black ailment, could not be reached for comment.

Passin contends in his suit that the sandwiches he serves at his restaurants "are an essential element in the success of Roy's and are the signal to consumers that call to mind the name of Roy's."

Roy's Place was originally in down-town Rockville, but was urban-renewaled out of there in 1970. It now has a menu that runs to 15 pages and includes 194 kinds of sandwiches.

The sandwiches include such combinations as the "Song of Love," a concoction of avocado, lobster, salad, bacon, lettuce, tomato and garlic dressing: "The Katherine of Tarragon, made with tarragon mayonnaise, melted swiss cheese and turkey, and the more expensive "Bender Schmender," which the menu says includes "corned beef, turkey, roast pork, chicken livers, brisket, sauce, lettuce, tomato and a psychiatric appointment.

Passin said in his suit that his combinations and recipes are "confidential and secret property" that were taken by Dickinson when he left Roy's place.

He also asserted in the suit that Dickinson kept in touch with current Roy's employees "to obtain from them additional confidence and trade secrets," and said Dickinson and other Dudley P's employes had conducted what amounted to scouting expeditions of Passin's restaurants to obtain more information.