1. Heat the olive oil or butter in a large skillet over medium-high heat. Once hot, add the chicken pieces in a single layer. Cook for about 4-5 minutes per side until golden brown and cooked through. Remove the chicken and set aside. I like to use chicken thighs here because they stay juicy, but breasts work if that’s what you have.
2. In the same skillet, add the chopped onion and sauté for 3-4 minutes until softened and slightly translucent. This is where your kitchen starts smelling like dinner is on its way—a smell that reminds me of my mom’s magic with simple ingredients.
3. Add the sliced mushrooms and cook for another 5 minutes until they release their moisture and start to brown. Stir in the minced garlic, smoked paprika, and thyme, cooking for an additional 1 minute until fragrant.
4. Pour in the chicken broth and Worcestershire sauce, scraping the bottom of the pan to lift any browned bits—this is flavor gold. Let the mixture simmer for 5-7 minutes until it reduces slightly.
5. Lower the heat to medium-low, then stir in the sour cream and Dijon mustard until the sauce is smooth and creamy. Be gentle here to avoid curdling; if you’ve ever had yogurt or sour cream split in a hot pan, you know exactly what I mean.
6. Return the cooked chicken to the skillet, stirring to coat it in that luscious sauce. Taste and adjust seasoning with salt and pepper.
7. Simmer everything together for another 2-3 minutes to let the flavors meld. If the sauce feels too thick, add a splash of chicken broth or water to reach your desired consistency.

From my experience, letting the sauce rest for a few minutes off the heat really lets the flavors settle. I often sneak a spoonful here, hoping no one’s watching because it’s that good.