For the chipotle aioli: Process the mayonnaise, cilantro, lime juice, honey, chipotle peppers and adobo sauce in a food processor until combined. Refrigerate for at least 1 hour.
For the sliders: Line a baking sheet with parchment. In a large mixing bowl, combine the chicken, taco season and oil. Form 12 patties roughly 1/2-inch thick and place them on the prepared baking sheet. Refrigerate for 30 to 60 minutes.
Prepare a grill for medium direct heat. Grill the sliders until the edges start to turn a lighter white and the juices pool at the top, about 3 minutes. Flip the sliders and place a piece of cheese on each. Remove the sliders when the cheese is melted and the internal temperature of the chicken hits 165 degrees F on an instant-read thermometer.
Place a slider on the bottom section of a bun, top with some aioli, watercress and the top section of the bun.