In a large skillet or pan, heat the olive oil over medium-high heat.
Add the chicken pieces and cook for 5-7 minutes, until browned and cooked through. Season with a pinch of salt and pepper as you cook.
Once cooked, remove the chicken from the pan and set it aside.
Sauté the Vegetables:
In the same skillet, add the butter and melt over medium heat.
Add the chopped onion and sliced mushrooms, cooking for 5-6 minutes until they soften and start to caramelize. Stir occasionally.
Add the minced garlic and paprika, and cook for another 1-2 minutes until fragrant.
Make the Sauce:
Sprinkle the flour over the onion and mushroom mixture (this step is optional, but helps thicken the sauce). Stir to coat the vegetables.
Gradually pour in the chicken broth, stirring constantly to avoid lumps. Bring the mixture to a simmer and cook for 3-4 minutes, allowing the broth to reduce slightly.
Add the Cream:
Reduce the heat to low, and stir in the sour cream (or heavy cream for a richer sauce) and Dijon mustard (if using). Continue stirring until the sauce becomes creamy and smooth.
Return the cooked chicken to the skillet, and simmer for an additional 5-10 minutes until everything is heated through and the sauce has thickened to your desired consistency.
Serve:
Taste and adjust seasoning with more salt and pepper if needed.
Serve the chicken stroganoff over cooked egg noodles or rice. Garnish with freshly chopped parsley for color and freshness.
