Combine the garlic, grilled tomatoes, orange zest and juice, cilantro, oil, vinegar, chile powders, chipotle puree and sugar in a food processor and process until smooth. Place the brisket in a large disposable pan, add the marinade and turn to coat. Cover and refrigerate for at least 4 hours and up to 24 hours.
Remove the brisket from the marinade 1 hour before putting on the smoker.
Prepare the ceramic cooker: Remove the grill grate and ceramic plate from the cooker. Add the hot hardwood charcoal and scatter the soaked wood chips over the top. Adjust the cooker to maintain a temperature of 225 to 250 degrees F. This temperature should be maintained throughout the entire smoke. Put on the ceramic plate. Put a pan with some of the apple juice on the plate, and then put on the grill grate.
Sprinkle the brisket on both sides with salt and pepper. Place the brisket, fat-side up, on your smoker grate and close it up for the long smoke.
Open your barbecue smoker every hour or two and spray the brisket liberally with apple juice to help keep the meat from drying out.
Once the internal temperature reaches 165 to 170 degrees F on a meat thermometer, after about 7 hours at the lower temperature range, the meat starts to get tender. At this point, wrap the brisket in foil this little trick is a big help in getting the meat tender, especially for beginners. Continue to cook until the meat reaches an internal temperature of 190 degrees F, 1 to 2 more hours.
Remove and let rest for 20 minutes before slicing. Remove the foil from the brisket over a large pan or disposable pan and reserve the liquid. Slice or shred the brisket. Toss in the reserved liquid.
To make the sandwiches: Split the rolls in half, oil the cut sides lightly, season with salt and pepper and grill, cut-side down, until lightly toasted. Spread some Horseradish Crema on the bun tops and bottoms. Top the bottoms with some of the meat, then some Caramelized Onion-Tomato Relish, then some lettuce. Top with the bun top and serve.
Whisk together the crema, queso fresco and horseradish in a small bowl. Season with salt and pepper. Cover and refrigerate for at least 30 minutes to allow the flavors to meld.
Heat the oil in a large saute pan over medium heat. Add the onions and slowly cook until caramelized, about 30 minutes, stirring occasionally. Add the tomatoes and cook until they just begin to break down. Add the garlic and jalapeno and cook for 1 minute. Add the vinegar and a pinch of sugar and cook for 2 minutes. Season with salt and pepper.
Transfer the onions to a bowl and add the cilantro. Let sit at room temperature for 30 minutes to allow the flavors to meld.