Chicken sausage gumbo for 15

5# sausage thin sliced fills up a gallon ice cream bucket
And I would think a thigh worth of chicken per person....

I’d have extra ready to go though

I make gumbo all the time for that amount people and often for many more. One whole fryer, 3 lbs. of good smoke sausage, as for roux, I just play it by ear since I make a lot of it when I fry chicken and use the oil with fresh AP flour to make my roux. With the oil I use for frying the chicken, I can usually get a quart jar of roux.

I also use okra that I grow in the summer months and smother down for later use for soups, gumbos, etc. For that amount of gumbo I'll use 2 quart bags of stewed okra. I also make my own stocks and will put a couple quarts of chicken or fried turkey stock in the pot to get things going. Of course the requisite trinity, garlic, green onions and other wet and dry seasonings go in the pot.

This amount of ingredients will yield me a bit more than 3 gallons of gumbo.