Mention that you like to eat sweetbreads, or a calf's thymus gland, to most people, and they'll look at you as if you're a little strange. But for some, they have almost a cult status, since it's so rare to find them on a menu. So imagine our delight when, exploring Canino Produce farmers' market, we saw a taco truck advertising mollejas, Spanish for "sweetbreads," on its menu board for $2 a pop. At Taqueria Tacambaro (2520 Airline), the sweetbreads are finely chopped, fried to a crisp on the griddle with onions and served in a tortilla with finely chopped cilantro and a slice of avocado. Tacambaro offers both a green and a fiery red hot sauce, but these tacos are so tasty, they don't need any help. You can bet that one won't suffice.