As that's the primary INGREDIENT
of baby powder...
The Big Bang Theory Season 4, Episode 21
And finally,
its main INGREDIENT is paneer...
The Big Bang Theory Season 2, Episode 21
and my favorite INGREDIENT
of all, uniformity.
The Big Bang Theory Season 5, Episode 24
I discovered
a secret INGREDIENT:
The Big Bang Theory Season 7, Episode 6
It was always Sheldon's favorite.
You know what the secret INGREDIENT is?
The Big Bang Theory Season 1, Episode 4