Season chicken strips with salt and pepper.
Heat olive oil and 1 tablespoon of butter in a large skillet over medium-high heat.
Sear chicken in batches until browned on both sides, approximately 3 minutes per batch. Remove chicken from skillet and set aside.
Add remaining 1 tablespoon of butter to the skillet. Sauté mushrooms and onions until moisture has evaporated and vegetables are golden brown, about 7 minutes.
Add minced garlic and cook for 60 seconds until fragrant.
Dust the vegetables with flour and stir constantly for 2 minutes to create a light roux base.
Gradually whisk in chicken broth, Dijon mustard, and smoked paprika, scraping the bottom of the pan to deglaze.
Return chicken and accumulated juices to the skillet. Simmer for 5 minutes until the sauce has thickened and chicken is cooked to an internal temperature of 165°F (74°C).
Remove skillet from heat. Temper the sour cream by stirring in a spoonful of hot sauce, then fold the sour cream into the skillet until smooth.
Serve immediately over cooked egg noodles and garnish with chopped parsley.