It was the hottest day of the summer thus far in Houston, and Chicano BBQ‘s pop-up tent offered little shade from the late-afternoon sun. Serafin Ramirez stood sweating in the parking lot of Tikila’s bar, surrounded by a portable flattop with sizzling burgers, a roiling deep fryer on wheels, and a hot box filled with barbecue. I yelled my order over the roar of a crawfish vendor’s propane burner next to where Ramirez has been setting up five days a week for the last two months. It was a scene that folks who are considering becoming pitmasters should witness before they take the plunge.But Ramirez doesn’t seem fazed. The 24-year-old Houston native has been making money from barbecue since high school. He used to take…