Preheat the oven to 400°F. Season the chicken breasts with salt and pepper on both sides.
In a large skillet, heat the olive oil over medium-high heat. Add the chicken breasts and sear for 5-6 minutes on each side until golden brown. Remove the chicken from the skillet and set aside.
In the same skillet, add the diced onion and cook for 3-4 minutes until softened. Stir in the minced garlic and cook for an additional minute.
Pour in the chicken broth, heavy cream, Dijon mustard, thyme, and paprika. Stir to combine and bring to a simmer.
Return the chicken to the skillet, cover, and reduce the heat to low. Let it simmer for 15-20 minutes until the chicken is cooked through and the sauce has thickened.
While the chicken is simmering, place the halved baby bok choy on a baking sheet. Drizzle with soy sauce and sesame oil, tossing to coat evenly. Roast in the preheated oven for 15-20 minutes until tender and slightly crispy on the edges.
Once the chicken is done, serve it on a plate with the creamy sauce spooned over the top. Add the roasted baby bok choy on the side and sprinkle with sesame seeds if desired.
Notes
For added flavor, marinate the chicken in the Dijon mustard and spices for a few hours before cooking.
To make it a one-pan meal, add sliced bell peppers or mushrooms to the skillet with the onions for extra veggies.