Preheat the oven to 350 degrees. Slice baguette in half vertically and hollow out the center of each half. Arrange bread on a baking sheet.
Shred the rotisserie chicken and toss the chicken with the BBQ sauce, turning to coat. Place the chicken in the hollowed out portion of the bread. Top each half with onion slices and place 1/4 cup of cheese on each half. Place sliced jalapenos over the cheese and place the pizza in the oven for 20 minutes. The bread will be golden and cheese will be bubbly. Remove the pizza and top with crumbled feta and cilantro just before serving.