Heat olive oil in a large skillet over medium-high heat. Season chicken pieces generously with salt and pepper, then sear for 4-5 minutes per side until golden brown. Transfer to a plate and set aside—the chicken doesn't need to cook through yet.
In the same skillet, sauté diced onion until softened, about 3 minutes. Add minced garlic and cook for 1 minute until fragrant and golden. This aromatic base creates the foundation for your cozy chicken skillet dinner's exceptional flavor.
Add diced potatoes, sliced mushrooms, bell peppers, and carrots to the skillet. Stir constantly for 3-4 minutes to coat vegetables in the flavorful oil. These heartwarming one pan ingredients should begin releasing their natural juices.
Pour chicken broth into the skillet and add dried thyme and rosemary. Return the seared chicken to the pan, nestling pieces among the vegetables. Bring the mixture to a simmer, then reduce heat to medium-low and cover. Let this warm weeknight meal cook undisturbed for 12-15 minutes until chicken reaches 165°F internally and vegetables are tender.
Remove the skillet from heat and stir in butter and heavy cream until melted and fully incorporated. Taste and adjust seasonings as needed. Garnish generously with fresh parsley before serving to add brightness and visual appeal.