My favorite diet meals became Wednesday dinners lamb and salad, according to the official rules. That opened the doors to Middle Eastern restaurants and their shish kebabs. It was a treat to diet on my $8 dinner at Arabian Nights, 2915 Connecticut Ave. NW. The waitress willingly left the rice off my shish kebab plate ($6.25) and substituted a salad of iceberg lettuce with tomatoes and green peppers. She even cheerfully exchanged it when it came with dressing on it. The kebab looked lonely on its plate, but the five cubes of meat were lean, aromatic and deliciously grilled. Faint Middle Eastern music and the rustle of beaded curtains accompained the meal, which I washed down with water and coffee (50 cents). True, the lighted pastry case was tempting, and everyone else was drinking wine. I kept my hands away from the warm pita edges, instead intensely contemplated the lamb. It was worth it. I would return for the charcoal grilled chicken ($5.35) or the beef kebab ($6.35) even if I weren't dieting.

Lamb day was also a joy at Le Gaulois, 2133 Pennsylvania Ave. NW, where I called ahead to find that I could get roast lamb -- requesting it without cream gravy and creamed spinach (which came anyway). The enormous portion, which I shared with table companions once I had my fill, cost $7.25. It was garlicky, lean and pink, glorious meat. I added a house salad that happened to be endive, watercress, mushrooms, tomatoes and crisp greens. Largely and pretty it was, and a dash of salt and fresh ground peper compensated for dressing. Be sure to ask for the house salad without beets if you are on a diet. Also, you can usually get a plate of shredded raw vegetables as an appetizer but again specify that dressing is not wanted. Le Gaulois is a good choice also for fish days, for the foil-steamed rockfish is fresh and juicy, fragrant with dill and tart with lemon. It comes with a potato, but that can be ignored. Unlike the lamb, it is always on the menu. There is usually a fine seasonal fruit salad. And on a fine fall day, the meal can be accompained by the entertainment of Pennsylvania Avenue's street life viewed from the outdoor tables. At Le Gaulois the tables need to be reserved ahead, and the pace is hectic, but the waitresses are patient and flexible.