Place chicken in a 4- to 5-quart slow
cooker. Season with oregano and cumin.
In a bowl, stir together soda, tomato
sauce and chipotles. Pour into slow
cooker, cover and cook on HIGH for 6
hours or LOW for 8 hours.
Heat oven to 350°. Remove chicken to a
bowl and pour liquid from slow cooker
into a saucepan. In a small bowl, blend
sugar, cornstarch and salt. Stir into a
saucepan along with vinegar. Place over
medium-high heat and bring to a boil.
Reduce heat to medium and simmer
3 minutes, until thickened and clear.
Shred chicken with 2 forks. Pour sauce
over chicken and stir to combine. Let
stand, covered, for 10 minutes.
Make sandwiches: Place a slice of cheese
on each roll. Bake at 350° for 2 to 3
minutes or until cheese melts. Divide
chicken among rolls. Add pickle slices
and, if desired, red onion.