Cook egg noodles according to package directions to al dente. Drain and set aside. (Tip: Do this while the stroganoff is cooking.)
In a small bowl, combine flour, paprika, remaining salt, and pepper. Set aside.
Melt butter with olive oil in a large skillet over medium high heat. Add in the onions and cook until they soften and begin to turn slightly brown on the edges, stirring occasionally; about 5 minutes. Add the garlic and cook an additional minute.
Add mushrooms. Sprinkle in ½ teaspoon salt. Cook until mushrooms begin to soften about 3-4 minutes. Continue to cook until liquid reduces by about half, an additional 2-3 minutes.
Sprinkle the flour-seasoning mixture over cooked mushrooms and toss to thoroughly combine.
Add broth, wine, and Worcestershire sauce to mushroom mixture and stir.Stir in spinach, cover with lid and turn heat down to very low. (I just turn it off.) The spinach will wilt in just a few minutes.
Just before serving, stir in sour cream and heat on low for a minute or two to bring it up to temperature. DO NOT BOIL.
Serve over cooked egg noodles.
Mushrooms: Cremini mushrooms, commonly marketed as baby bellas or baby portobellos mushrooms, are simply juvenile portobello mushrooms. You may also find cremini mushrooms marketed as cremino, common brown, and Roman mushrooms.Worcestershire: Regular Worcestershire sauce is made with fish sauce or anchovies, so it isn't vegetarian. If you want to keep this recipe wholly vegetarian, simply use a vegan W-sauce.Serving: Traditionally, stroganoff is served over wide egg noodles. You can mix them into the sauce before serving, or serve the sauce separately over hot noodles. (For ease of serving, we prefer to mix them in.)We also enjoy this recipe served over brown or white rice.