Thai Food

Thai food from Siam Palace is what the boys eat on Mondays. ^[1]

In "The Big Bran Hypothesis" (S01E02), Howard eats Pad Thai without peanuts.
In "The Cooper-Nowitzki Theorem" (S02E06), Sheldon eats Mee Krob and chicken satay with extra peanut sauce.
In "The Adhesive Duck Deficiency" (S03E08), Sheldon reduces his "usual" order to one quarter of the Assorted Appetizers Plate and one half of the Golden Treasure for two, as he eats alone.

Trivia

In "The Big Bran Hypothesis" (S01E02), Sheldon points out, that they eat Thai food with forks not with chop sticks.
In "The Monopolar Expedition" (S02E23), the guys eat rehydrated Thai food when living at the magnetic North Pole.
In "The Locomotive Manipulation" (S07E15), Leonard and Penny want to sneak out of the vet's office where they took Cinnamon to get some Thai food.
In "The Veracity Elasticity" (S10E07), Sheldon wants to get some Thai food near Amy's Apartment and to check on the plumbing repairs. Amy doesn't want to because she lied to him.
Howard has to take care that the food doesn't contain peanuts due to his peanut allergy. Leonard states that every Thai restaurant in towns knows this and welcomes him with "ah, no peanuts boy". ^[2]