Hrm. Haven't heard of it (but we don't get a whole lot of Puerto Rican food up here in the Northwest) but a quick googling out of curiosity led me to recipes that were all quite different. Maybe it's like paella: Rice and whatevah ya got on hand. But I'll stay tuned here to see if anyone in-the-know posts some wisdom.

i've never heard of this particular dish but my ex sister in law is puerto rican and she cooked all her rice dishes the same way, basically. oil and flavorings in a heavy bottomed pot and then added rice & water & whatever else at the appropriate time.

the secret may be in the spicing you're experiencing (you can always ask the restaurant chef, that sometimes gets results) but if it's the method i'd try that. of course, a cast iron dutch oven is probably a great way to go; definitely a heavy bottom pot! lid only part of the time if you're cooking the rice in that pot and you want that crunchy stuff @ the bottom (pigao?) to form properly.

this seemed close, method wise:
www.fsafood.com/fsacom/Rec...k+Beans.htm

good luck! i'll keep checking in for more ideas cuz it sounds yummy to me!