Bettas will nip at anything that looks like food. It doesn't mean that what they nip at is good for them.
BettaSmart: My personal blog dedicated to ending the myths and misconceptions on Betta fish care through educational articles. Topics range from basic care to raising awareness about the dangerous marketing practices in the fish world.
Peas are more for goldfish, but as bettas are the bottomless pits of the fish world they'll eat anything their mouth fits on, and tastes good to them they tend to get their veggies through their live prey, which is why many people suggest frozen or live foods.
Breed for the breed, not for the money; the words any REAL breeder would understand.
You must know nothing in order to know all, for all is nothing and nothing is for all.