YEA, for six days the kitchens of the Conrad Hotel do labour on preparing beasts and fowl and herbs of the earth and are fruitful in their work. ''So on the seventh day, the Conrad is allowed to go a little bit crazy. And that craziness they do call the Sunday Brunch. ''Hallelujah!'' Pardon the Biblical paraphrasing, but for lovers of fine food - and endless fine food - the Conrad Hotel Sunday Brunch is virtually a religious experience. The atmosphere is exhilarating, glittering, luminous. In fact, the very opposite of those monstrously repellent cabal of statues outside the hotels. The trick is: a) to make reservations for the Sunday brunch at least two days in advance; b) avert your eyes from the statues and the gloomy lobby; and c) take a private elevator to the Eighth Floor. Here is an experience of freshness and (on the right mornings) eternal light. You have a choice of two settings: the pastel shades of Nicholini's, or the French posters of The Brasserie. Both restaurants have gorgeous picture windows looking on differentaspects of Pacific Place. The service is friendly and relatively knowledgeable. Ask the most innocent waitress about the coffee, and she gives a detailed explanation. Ask the waiter about the seafood, and he'll discuss crustaceans. The information isn't always correct, but eagerness excuses imagination. The music is partly live piano, partly recordings of l930s French chansons. The newspapers are the local dailies or four-day old Le Monde, Corriere della Serre and Figaro. The Sunday Brunch began as a kind of gimmick when the Conrad opened three years ago. Then, according to Assistant Manger Daniel Ra, it was confined to The Brasserie. As its popularity grew, it (as well as the waistlines of its regular customers) expanded. These days, two chefs man the pasta table, two chefs do waffles and omelettes, one does the crepes and two or three others wander in and out. About 15 chefs work in the kitchen while the waiters and waitresses roam the two restaurants and the corridor, where most of the tables are set up. They actually do give a meaning to the word ''brunch.'' When I was growing up, brunch meant that, besides juice, cereal, milk, coffee and bread, there'd be some cheese and maybe a few pieces of salmon. The Conrad not only has brunch brunch, but it's so sumptuous and at such a relatively low price - $218 including a glass of French sparkling wine - that you may have a chance to actually bankrupt the Hilton chain. Start innocently with some juices. The orange and grapefruit is fresh, but others like grape, apple, and V8 come from the can. Now walk around the bakery items. But avoid them like the plague. They'll only fill you up. Here are prunes Danish, cinnamon rolls, croissants, muffins, brioche and rolls freshly baked from the night before. Now get on to the expensive stuff. Start to make the Hilton accountants nervous. We started with the Norwegian salmon. First we had the hot baked salmon with spinach en croute. Then we added some poached salmon and smoked salmon. And for good luck, two different Japanese salmon sushi to the plate. Moving on to the ocean of seafood. The huge lobster-like things are king prawns, the smaller river crayfish-looking crustaceans are Australian yabbies. They - as well as the New Zealand mussels, Scottish rock oysters, sashimi, sushi, garoupa salad and herring salad - taste as bright as the morning. The salads are appetising. Here are dozens of market salads, with four different lettuces, tomatoes, etc, along with half-a-dozen home-made dressings. The Conrad also puts out ''marinated'' salads. These include beef, mozzarella cheese salad, sausage andcheese, marinated Greek salad with Feta cheese and tuna fish. Along with this are German cold cuts, superb suckling pig skin, Bayonne ham and the usual selection of quiches. The crepes look opulent. The blueberries, raspberries and cherries are crunchy and sumptuous, and the choice of dressings are obviously for the rich. There are too many hot items, ranging from the mundane (fried rice, lasagna, marinated pork) to the exotic (marinated chicken with lemon grass and coriander). But the Conrad has a surprise with the hot items. For along with the buffet, there's a special menu - and a rather misleading one actually. It states, ''Choose your appetiser (sic) . . . and as your main course, sample one (sic) of the . . . hot dishes listed below. First, the buffet is not an ''appetiser''. It is an infinite cornucopia. Secondly, you can have any or all the hot items. We couldn't resist the poached eggs on muffin with lobster medallion. Next week perhaps the Tasmanian lamb chop or curry-flavoured river lobster. The dessert table is terrifying. We won't even mention the chocolate truffles or the chocolate mousse. The raspberries and blueberries are from America. But now imagine the chocolate cups filled with mocha mousse, or the hazelnut chocolate vermicelli on iced meringue or the apple strudel, which could have done with some cinnamon actually. Now for the cheese on the buffet. Some hotels are skimpy, others are mean. The Conrad takes a different direction. One cheese. One whole cheese. In fact, a whole Brie. ''With food like this,'' says the assistant manager, ''we think of the brunch as a promotion. We want people to come here and think about coming back to The Brasserie later on.'' Champagne, no matter what the waiter says), read the paper, and leave a happier (if somewhat stouter) individual. Frankly, anybody can make an expansive brunch. But a brunch of such taste, freshness and obviously posh ingredients is as rare and wonderful as the Christmas season. Brasserie and Nicholini Sunday Brunch, The Brasserie and Nicholini restaurants, 8th floor, Conrad Hotel, Pacific Place. Tel. 5213838; open: Sundays, 11 am-3 pm.