Middle Primitive Elvish
ap
root. ?cook
aya
root. other, different (of larger numbers)
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
The root √AP appeared in The Etymologies of the 1930s as the basis for the words ᴹQ. apsa, N. aes “meat, cooked food” (Ety/AP). Tolkien glossed this root as “cook” which he marked with a “?”, then deleted the gloss (EtyAC/AP). Despite this deletion, I’ve seen a few Neo-Elvish writers use this root as the basis for verbs “to cook”, but I personally find this problematic as such forms tend to collide with words like Q. apta- “to refuse” < √BĀ/ABA. I prefer to retain the Early Qenya and Gnomish words ᴱQ. maxa- and G. brath- for “to cook”.