NEW YORK — Elaine Bloom’s Passover seder was interrupted one year when several guests had to leave unexpectedly to care for their child. The meal was delayed while another guest took them home.

Bloom figured her main course, salmon fillet, would be inedible. “My salmon was in the oven for over two hours,” said Bloom, a professional organizer with a business called A Place For Everything in Maplewood, N.J.

But the salmon “came out fabulous,” she said. She’d roasted the fish, along with a few other ingredients like wine, butter, garlic, dill and lemon, in an oven bag.

By accident, Bloom discovered that it didn’t matter how long the dish cooked. “If the seder is an hour shorter or an hour longer than you think it will be, it’s fine. Now I make that salmon every year.”

Flexibility, forgiving recipes and advance preparation are the keys to a successful seder - or any other feast where you have numerous guests, multiple courses and you can’t be certain when the food will be served.

This unpredictability is especially true of a seder, the ritual feast held to celebrate the Jewish holiday of Passover. Prayers, songs, games, and a retelling of the Biblical story of Exodus precede a multi-course meal that can include hard-boiled eggs, gefilte fish, matzoh ball soup; a main course of brisket, fish, chicken or lamb; and special desserts like sponge cake and flourless tortes. You can’t predict how long the ceremonial aspects of the meal will take, so you never know when you’ll be sitting down to eat the roast or the fish.

“It’s the hardest meal to orchestrate,” agreed Joan Nathan, a James Beard award winner and author of many cookbooks, including “Jewish Cooking in America.” Nathan expects 40 guests at her seder.

Despite all the work involved in hosting a seder, “for many Jews, it’s the warmest and most meaningful holiday of the year, perhaps the only time that person thinks about what it means or what they want it to mean, to be a Jew here and now.” said the novelist and poet Marge Piercy, who’s just come out with a new book called “Pesach For the Rest of Us: Making the Passover Seder Your Own.” (Pesach is the Hebrew word for Passover.)

Liberation is the theme of the Passover story, and the following tips can help liberate you from the stress of organizing the big meal, whether you’re making a seder or any other feast.

• Make to-do lists and start shopping far in advance. “Go through your menu recipe by recipe and put the shopping list together,” said Sandra Blank, editor of “The Kosher Palette” and “The Kosher Palette II.” “That to me is the most overwhelming part, but you can do that weeks ahead of time.”

Nathan keeps her list stored in the computer, which makes it easy to update the next year. As the big day approaches, she said, “I love crossing things off.”

Don’t forget chores like making place cards, and borrowing or buying a fold-out table, extra chairs or silverware to accommodate your crowd.

• Start cooking well before the big day. “I am a big advocate of things that can be made ahead of time,” said Blank, including soups, main courses, salad dressing, side dishes and desserts.

If you have freezer space, you can make many dishes a week or more beforehand, then freeze and defrost the day before or the day of the seder. Sponge cake “freezes like a dream,” said Nechama Cohen, author of “Enlitened Kosher Cooking.”

Soup can be frozen in a plastic container and defrosted by running the container under hot water until it loosens.