Cook potatoes in salted boiling water until tender, drain, set aside.
Add the juice of 2 lemons, chicken base, thyme, garlic, Dijon and water in a small bowl then whisk to combine and set aside. (Do not discard lemon halves)
Sprinkle chicken liberally with salt and pepper on both sides. Heat oil in a large non-stick skillet on high heat. Add chicken and sear for 4-5 minutes until brown and seared. Flip and brown other side.
Lower heat to medium-high then add liquid and reserved lemon halves to the skillet, cover, and continue cooking until internal temperature of chicken is 165°. Flip chicken over halfway through cooking to keep covered in sauce and moist.
Remove lid then add 2 tablespoons of butter and allow to melt into the sauce. Remove chicken and place on platter. Add potatoes to the pan and toss. Pour over chicken, sprinkle with a little more salt and pepper, and serve immediately.
Notes
Bone-in, skin on chicken breasts or chicken thighs would also work great in this dish.
Use a meat thermometer to ensure perfectly cooked chicken.