The closest to what you are looking for is Dac's, on 30th ave, 1 block north of Constituentes. Not many places sell prepared food, but Super Carne on 1st. st south (1 block south of Juarez) between aves. 25-30 has excellent take-out arrachera, roasted onions and potatoes, starting around noon. And the little ladies selling cups of fresh fruit under the banyan trees by the dock are worth a visit.