Hot dish, the Minnesota-specific church-supper stalwart that cooks in other parts of the country might mistake for a casserole, is no stranger to hard work.

Early versions of the dish — traditionally a mix of protein, starch and vegetables held together with a creamy sauce baked until it bubbles — helped conserve meat during World War I and fed farm families during the Depression. Topped with Tater Tots or mixed with rice, more modern renditions offer working parents an inexpensive way to get dinner on the table after a long day.

Now, hot dish has been conscripted to help Amy Klobuchar, the senator from Minnesota, win the Democratic nomination for president.

In a series of events that began in New Hampshire last summer and continued this month in Iowa, Ms. Klobuchar has been feeding her recipe, blanketed in Tater Tots, to voters at gatherings the campaign calls Hot Dish House Parties.