"Yes, we're here to butter up Congress, to make them say cheese," admitted Robert F. Anderson, executive director of the American Butter and the National Cheese institutes. Ash Wednesday looked more like Fat Tuesday and all that jazz last night as the Caucus Room of the Cannon House Office Building flowed with buttermilk, if not honey, as well as:

Butter whipped with rosemary, mustard, onion, celery seed, mint, poppy seed, curry, dill, parsley, sage, horseradish, sweet basil, tarragon, watercress, anchovy, caper, apple, bernaise and Martha Washington's orange recipe.

All-American cheese included Wisconsin Better Cheddar, Vermont Style Cheddar, cream cheese with scallions, Monterey Jack, mozzarella, Munchee, feta, Baby American Swiss, Blue Cheddar, Munster, among others.

"Well, we couldn't get the room on Mardi Gras," said Anderson.

For butter or worse, Siert Riepma of the National Association of Margarine Manufacturers came to pay his respects. "Butter's great for people who want to eat it," he said, adding that his association wanted to make sure that people who'd rather eat margarine won't have it taxed off the table.

Though 200 members of Congress accepted the invitations, as usual at these affairs, many of the 400 attending wore tags saying "From the office of Congressman . . . " The free meal on Capitol Hill has long been a perk of overworked and underpaid congressional staffs.

Brian Folkerts and Karen Finch represented Rep. Lynn Martin (R-Ill). Finch said, "He's cheese, I'm butter."

Rep. Robert A. Young (D-Mo.) said he came along to keep his chief legislative aide Mike Talisnik in line. Sally Shafroth, his executive secretary, said she'd eaten both butter and cheese.

"Cholesterol? What the hell is that?" said Young.

"I think everybody should eat as much as they want," said Mary Ann Meloy, White House public liaison, who handles everything from guns to butter. "My parents were always taking me to the doctor because I was so thin. I get tired of people calling me 'little lady.' You shouldn't judge people by size."

As for dieting's effect on agriculture, Richard Goldberg, deputy undersecretary of agriculture said, "There's no way of knowing how much, but I'm sure it's not the main problem. Too much production is one of them. We do give away cheese and nonfat milk."

Agriculture Secretary John Block couldn't make it, Goldberg said, because he had to go to the British Embassy dinner for Prime Minister Margaret Thatcher.

Maryland Reps. Beverly Byron (D) and Helen Delich Bentley (R) -- neither of whom look like they ever ate a spoonful of calories (though Bentley is well known for the richness of her East European New Year's spread) -- stood drinking soda water and abstaining from the table of cheeses. Anderson pressed bread and herb butter on the two for a photograph.

Rep. Robert Lagomarsino (R-Calif.) and his wife Norma said they believe in "moderation" when it comes to cholestrol. But Norma Lagomarsino told a tale about a man who'd been taking Tums (500 mg calcium) and took a bad fall without injury. In the brittle bones circle, Tums has become a trendy source of calcium.

Rep. Chip Pashayan (R-Calif.), who observed, "I've had so much of this sort of thing I have to watch out now," said his fiance'e, Sally Christian of the White House Visitor's Office, wasn't with him that evening, but not because she has anything against butter and cheese.

Tuckie Bartlett, another woman with a skim milk figure, represents Kraft Inc., one of the big cheeses. "I live on cream cheese," she said.

Pashayan agreed there is no justice.