I think this depends on the country. As a Costa Rican I say "frijóles", but my Colombian boss says "fríjoles". Technically, though, I guess that the rules of the accent tell me that it should be pronounced as we do in Costa Rica. There are rules for this that you can actually learn so that you don't need to wonder :) they might be a bit complicated, but anyway: https://www.uv.es/ivorra/cosas/acentos.htm One more thing: some Latin American countries call frijoles "porotos".

Saludos Geri. Hay tantas opciones para nombrarlos como variedades de frijol: http://lema.rae.es/dpd/srv/search?id=WEo7DBq5vD6Ua7D32h