Each Venue has 5-7 different customers attending it. Customers appear in the Venue they are introduced, and appear in the next few Venues as well.
Find Rosie, Barb, Bernie, Kingston, and Norbert in Table Steaks.
Find Violeta in Taco Train.
Find Maddie in Adventurous Eats.
Find Hennui in Metal Chef: Italian.
Find Tira in Cutie Cakes.
Find Patty in Barnyard BBQ.
Find Umiko and Skip in Enso Sushi.
Find Big Bob Lugman in Caveman Paleo.
Find Doug Howt in Out n' Inning.
Find Maid Mary Ann in Medieval Dines.
Find Alice in Wonderland Delights.
Find Pat Smee in Pieces of Ate.
Find Kitty Kate in Cat Lady Crepes.
Find Harold T. Rumpet in Chew Orleans.
Find Darragh in Zero G Pizzeria.
Find Karlo in Lava Luau.
Find Franklin in Feastival of Lights.
Find Peter in Chateau Creep.
TIP: Since the Super Customers usually appear by the fourth season in a venue, choose an episode there so you can pick the recipe you want.