Preheat oven to 425F.
Mix lemon sauce ingredients: In a small bowl or liquid measuring cup, whisk together the chicken broth, lemon juice & zest, honey, dijon mustard, garlic, chopped rosemary, salt & black pepper. Then set the sauce aside for later.
Prep potatoes: Wash the potatoes and cut them in half if they're on the small side or quarter them if they're a little larger.
Brown chicken: Season the chicken thighs on both sides with a generous pinch of salt and black pepper. Then heat a pan over medium heat, add 2 Tablespoons of oil, and brown the chicken on both sides (2-3 minutes per side).
Add potatoes and lemon sauce: Transfer the browned chicken to a roasting pan, along with the quartered potatoes and the lemon sauce poured over top of the chicken and potatoes. Add some optional lemon slices over top if you like.
Bake: Then bake in the oven for 30-35 minutes, uncovered. The chicken should be cooked through (165F is the proper internal temperature) and the potatoes should be cooked (you can test them with a fork). Serve the chicken and potatoes with a spoonful of the delicious lemony sauce from the bottom of the pan. Enjoy!