The original carreteiro is peasant food. Made of rice and salted meat, it was easy to prepare in a era without refrigeration. By the way, carreteiro means carriage's driver, someone that wanders on horse power with very few resources. Today we call carreteiro rice with all kinds of meat cuts and even with leftovers of a good churrasco, or barbecue. My favorite.
I start with chopped onions on hot olive oil, salt, and pepper. Then comes the meat, the rice and enough water. Sometimes, tomatoes or even (what a heresy!) catchup. Sorry for that, Clarissa! Next comes the secret: after the rice, after have added the water, leave it alone! Don't touch anything. Get everyone out of the kitchen, do not speak loud! The rice should cook on low heat with the pan semi-closed. You should watch it carefully, adding water when necessary, but never, never, stirs.
Well, then came a wife and a doughter that like their rice glued like a puree. The technique, passed from one generation to the next, is lost. A tradition is dead.