In a small bowl, combine mustard, shallot, garlic and salt & pepper. Rub chicken breasts with this mixture and place into crock pot. And then add in carrots.
Sprinkle ½ of the tarragon over chicken and carrots. Cover and cook on low for 5-6 hours.
Transfer chicken to a separate plate, and pour crock pot juices into a medium sized sauce pan, and bring to a simmer over high heat.
In a small bowl, combine cornstarch and half &half. Whisk the mixture into the saucepan, and stir constantly until sauce is thickened and velvety – about 3-5 minutes.
Pour sauce over chicken, and top with remaining fresh tarragon.
Notes
Entire recipe makes 4 servingsServing size is 1/4th of dish