YVES MONTAND (Jean de Florette), and Luis and Daniel Valdez (La Bamba) were in town recently to promote their films. With Montand, it was wine, salad, strawberries and hand gestures at the Embassy Hotel. With the Valdez brothers, it was Mexican chow, Cervezas beer and hand gestures at Enriqueta's. And all three had mouthfuls of enthusiasm for their movies.

Director Claude Berri "built a little trap," Montand said, recalling how he was roped into playing the pivotal role in the diptych film "Jean" and Manon of the Springs. Montand, although a fan and friend of the late Marcel Pagnol (whose book "L'Eau de Collines" is the basis for the film), was on a singing tour and had no desire to make a film, particularly in a role that made him look older. But after doing a screen test as a favor to Berri in 1984, Montand was impressed with the result and agreed to ditch the singing. They started shooting both films the following year. Berri had to shoot in sequence with the seasons over nine months, filming 461 scenes in all. "Tre`s fatiguant," said Montand.

Ce'sar 's part is "sympatique," said Montand of the character who plots the demise of farming novice neighbor Jean de Florette so he can own Florette's land. "I think he's nasty, but basically not a criminal. With Jean de Florette {Ge'rard Depardieu}, sometimes I laugh at him. Sometimes I want to take the fool and show him how to do it."

Montand has often reread the screenplay, written by Berri and Ge'rard Brach (who also wrote scripts for Polanski's Tess, The Tenant and Repulsion , as well as The Name of the Rose and Berri's The Two of Us). "I read it sentence by sentence and still" -- here Montand mimes a karate chop to the throat -- "baboom!"

The impetus for "La Bamba" started in 1972 when Taylor Hackford and Daniel Valdez decided to make a film about Ricardo Valenzuela, better known as Ritchie Valens. Other projects, including Hackford's Officer and a Gentleman and Against All Odds, as well as the Valenzuela family's reluctance to cooperate, kept the project on ice until the 1980s. Finally Valens' mother Connie and brother Bob began to talk and Hackford had the credentials to get the project moving. Hackford brought in Daniel's brother Luis -- founder of El Teatro Campesino, a California comedy skit troupe formed to portray the plight of farm workers -- to write the script. Hackford eventually let Valdez direct as well.

While writing the script (which he says is "about 80 percent true"), Luis Valdez interviewed Valens' family and friends and found "no one was willing to say anything negative about Ritchie. Eventually I was convinced Ritchie was as people described. He was a very good kid . . ."

By the time they were ready to shoot, Daniel Valdez had grown too old to play Ritchie. So Esai Morales and Lou Diamond Phillips were brought in to read for Ritchie and Bob, respectively. After their auditions, however, director Valdez gave the two actors the opposite roles. "Esai would have been a dead ringer for Bob in the 1950s," said Valdez. "Ritchie was more different in appearance from Lou. But Lou's spirit and his personality were like Ritchie's . . . There's a fine line between reality and art here."

This weekend, Friday through Sunday, Sidwell Cinema features a "Beat Generation film celebration." The fare includes a Woody Woodpecker cartoon called Beat Beatnik (Real Gone Woody); Towers Open Fire, written by and featuring William Burroughs; and Pull My Daisy, a 1959 film made by Robert Frank and Alfred Leslie which features Allen Ginsberg, Gregory Corso and Peter Orlovsky. Tickets are $3.50. Showtimes on Friday and Saturday at 7:30 and 9:05 (plus a Saturday 10:45), and Sunday at 7 and 8:35. Call 537-8135 for more information . . . Sidwell also invites local filmmakers to submit their 16mm films (shorter than 30 minutes) for its Washington Area Independent Film Festival to be held the weekend of August 7. Call Ellis Turner or George Lang at 537-8133.

Tuesday at 8, the Smithsonian Resident Associates will screen Paris Express, Harold French's 1952 British adaptation of the Georges Simenon novel, "The Man Who Watched Trains Go By." It stars Claude Rains, with Herbert Lom and Marius Goring. The film, part of a Simenon festival, will be introduced by festival director William Claire. Admission, at the American History Building's Carmichael Auditorium, is $6.50, $5 for members. Call 357-3030.

The Big Easy, described as a "New Orleans-based film noir about drug trafficking," will have its Washington premiere at the American Film Institute Thursday at 6:30. Written by Daniel Petrie (part of the Beverly Hills Cop writing team) and directed by Jim McBride, maker of the cult film David Holzman's Diary, it stars Dennis (The Right Stuff, Innerspace) Quaid.

Also on Thursday (noon, free) is Compulsion, featuring Orson Welles as attorney Clarence Darrow, at the National Archives Theater on the Archives' fifth floor. Call 523-3000.