Start by combing the thyme, smoked paprika, salt, and pepper. Rub the spices on the outside of the chilled duck breasts. Place the duck skin-side down in a cold pan and turn the heat on medium-high.
Let the duck brown for 3 minutes or until it starts to render out some fat. Seal the duck up in a plastic bag and cook the breasts in a water bath at 131°F for 1-1/2 to 2 hours.
Take the duck out of the bag and brown it, skin side down, in a hot pan until it is nice and crispy, this usually takes a couple of minutes.
Let the duck rest for a few minutes before slicing it on the bias and serving.