A “booyah” is a thick soup or stew and is probably derived from the French word “bouillon” (broth). “‘Boo-Yah’ is a very popular soup among the boys on Humboldt creek” was cited in an 1877 Kansas newspaper. “Dished up a roasted ox and 200 gallons of his famous ‘Boo Yah’” was cited in an 1894 Michigan newspaper.
“Booyah” meaning “an event where booyah is served” was cited in 1903.
The book The Flemish in Wisconsin (1985) asserts that booyah was invented and named by Andrew W. Rentmeester in Wisconsin in 1906, but this is not true.
Wikipedia: Booyah (stew)
Booyah (also spelled booya, bouja, boulyaw, or bouyou) is a thick soup of probable Belgian origin made throughout the Upper Midwestern United States. Booyah often requires up to two days and multiple cooks to prepare; it is cooked in specially designed “booyah kettles” and usually meant to serve hundreds or even thousands of people. The name also refers to the event surrounding the meal.
Etymology The term "booyah" may be a variant of "bouillon". It is thought to have derived from the French language words for "to boil" (bouillir), and subsequently broth (bouillon). The spelling with an H has been attributed to the phonetic spelling by Wallonian immigrants from Belgium. The Dictionary of American Regional English attributes the term to French Canadian immigrants; others attribute it to a derivation from the Provençal seafood dish bouillabaisse.
25 August 1877, Junction City (KS) Union, p. 5, col. 1:
“Boo-Yah” is a very popular soup among the boys on Humboldt creek.
1 September 1894, Detroit (MI) Free Press, “Isabella County Farmers Enjoyed Themselves,” pg. 4, col. 7:
Anthony Graves had charge of the culinary department and dished up a roasted ox and 200 gallons of his famous “Boo Yah.”
30 July 1903, Minneapolis (MN) Journal, “The Nonpareil Man,” pg. 4, col. 6:
The Backyard Weekly, published in St. Paul, tells of a “booyah” given by Moochgi Moochers. These society affairs are getting about as difficult of comprehension as golf slang.
28 October 1911, Calumet (MI) News, “Red Jacket Business Directory,” pg. 4, col. 6:
Chicken “Booyah” on Thursday and Saturdays.
27 November 1912, Duluth (MN) News Tribune, “Bovey Hunter Gives The Town Moose Meat Feast,” pg. 3, col. 2:
A huge “booyah” was also made of venison and his place of business was the point of interest all day and evening.
10 August 1914, Winnipeg (Manitoba) Tribune, “Fish Stories, True and Otherwise,” pg. 5, col. 5:
The fish which I gave to the Boy Scouts to make boo yah (that’s what they call fish soup) out of, weighed 79 lbs, 2 oz; and measured six feet one and three-quarters inches in length with an average width of one foot two inches.
8 August 1915, Rockford (IL) Morning Star, “Vicinity Lodge Notes,” pg. 12, col. 4:
Green Bay Odd Fellows will hold their annual “booyah,” which is a stag outing event, next Sunday.
De Vlamingen in Wisconsin = The Flemish in Wisconsin
By Jeanne Rentmeester and Les Rentmeester
Wisconsin: J. and L. Rentmeester
Because chicken booyah is not only a delicious meal but is also the name for a social event, a history of the CHICKEN BOOYAH is included with the recipe. The spelling of the word is unusual and happened in the following way. When Andrew W. Rentmeester took over as teacher in the one-room Finger Road School in 1906, he suggested to the school board that a picnic be held to raise money to buy much-needed supplies for the school. It was decided that a thick chicken soup (known as chicken bouillon) would be made by his mother from ingredients donated by parents of the school children and would be offered for sale. When Andrew (known as “Teacher” in the community) put an advertisement for the upcoming event in the Green Bay Press Gazette, he was asked how the word bouillon was spelled. Not knowing how to read French, he spelled it b-o-o-y-a-h>