Take the chicken out 20 minutes prior to cooking. Pat dry and make shallow cuts (about ¼”) along the top of the chicken breast.
Add a small drizzle of olive oil and rub on both sides of the chicken. Season both sides with salt, pepper, garlic powder and thyme.
Grab a pan and heat for 1-2 minutes over medium heat. Then add 2 tbsp olive oil. It should be shimmering.
Lay the chicken breast, away from you, in the pan and sear for 3-4 minutes (depending on the thickness of the chicken) on each side. It should be golden on each side and pretty much cooked through - I like to pull it once it reaches 160 degrees as it will rest for about 5 minutes and reach 165 degrees during the resting period. Rest on a wire rack with a baking sheet underneath while we make the sauce.
Reduce the heat to medium-low and add in 1 finely minced shallot, 3 cloves of finely minced garlic and stir for about a minute. You want this softened but not browned.
Add in the chicken stock and increase the heat back to medium and let this bubble until it reduces by half.
Add in the dijon mustard and stir (or whisk until incorporated) for a minute.
Add in the heavy cream and stir for another minute.
Add in the 2 knobs of cold butter and stir until incorporated and then remove from the heat. Add a squeeze of lemon to finish off the sauce.
Slice up the rested chicken breast and spoon the sauce all over. Finish with chives!