Season the chicken with thyme, salt, and pepper.
In a skillet, brown the chicken over medium heat in the vegetable oil.
Drain the pineapple slices, reserving the juice.
In a small bowl, mix the cornstarch with 2 oz. of the reserved pineapple juice and set aside.
In another bowl, combine the remaining pineapple juice with Dijon mustard, honey, and minced garlic.
Add the Dijon mixture to the pan, reduce the heat, and cover. Let it simmer for 15 minutes.
Remove the chicken from the pan.
Stir the cornstarch mixture and add it to the pan, bringing it to a boil.
Stir for 2 minutes to thicken the sauce.
Lower the heat and return the chicken to the pan, flipping it to coat evenly with the sauce.
Add the pineapple slices to the pan, placing them on top and around the chicken. Cover for 2-3 minutes to warm the pineapple through.
Serve the chicken and pineapple over the cooked rice.