Preheat your oven to 400°F (200°C).
In a large mixing bowl, toss the halved baby potatoes with olive oil, garlic powder, onion powder, salt, and pepper until evenly coated.
Spread the seasoned potatoes in a single layer on a baking sheet. Roast in the preheated oven for 20 minutes.
While the potatoes are roasting, season the chicken thighs with salt and pepper. In a large skillet over medium-high heat, sear the chicken thighs for about 5 minutes on each side until golden brown.
In a separate bowl, whisk together the heavy cream and Dijon mustard until smooth.
After the chicken is browned, reduce the heat to low and pour the Dijon cream sauce over the chicken in the skillet. Allow it to simmer for about 5 minutes until the sauce thickens slightly.
Once the potatoes have roasted for 20 minutes, remove them from the oven and add them to the skillet with the chicken and sauce. Stir gently to combine.
Return the skillet to the oven and bake for an additional 15-20 minutes, or until the chicken is cooked through and the potatoes are tender.
Garnish with chopped parsley before serving.