Preheat your oven to 400°F (200°C) so it's ready when you need it.
Heat the olive oil and 2 tablespoons of butter in a skillet over medium heat until bubbly.
Season the chicken breasts with Italian blend seasoning, salt, and pepper. Place them in the skillet and cook 5-7 minutes each side until golden brown on outside.
Remove chicken from skillet and set it aside while you work on the potatoes.
Add baby potatoes to the same skillet and cook for about 5 minutes, stirring here and there.
Stir in minced garlic and cook together for about 1 minute until aroma hits you.
Pour in chicken broth and add dijon mustard, give it a good stir to mix everything up. Nestle the browned chicken back in among the potatoes.
Put the skillet in the oven and roast everything for 20-25 minutes until chicken is cooked through and potatoes tender. Finish by stirring in remaining tablespoon of butter, season more if needed, and serve.