Pat the steaks dry, rub with 1 Tablespoon olive oil and season with salt and pepper.
Heat a medium nonstick skillet over medium heat.
Place the steaks in the skillet and cook to desired doneness; about 5-6 minutes per side for medium-rare (145 F) to (160 F) for medium.
Remove steaks to a plate, lightly cover (don't seal) and set aside to keep warm. Steaks will continue to cook as they rest.
In the same skillet, over low heat, add the remaining 1 Tablespoon of olive oil and the butter.
When butter is melted, add the mushrooms and saute until mushrooms are tender; about 5 minutes.
Add shallots (or onions) and garlic to the skillet and saute for 2-3 more minutes.
Transfer the mushroom mixture to a bowl and set aside.
Using the same skillet, turn the heat to medium-high and add the wine, beef broth and thyme and bring to a boil, stirring to remove any browned bits at the bottom.
Add the whipping cream and bring to a boil.
Combine cornstarch and water in a small bowl until well blended.
Add 1 Tablespoon of the cornstarch mixture to the mushroom sauce; stir and cook until slightly thickened, adding more cornstarch mixture, if needed. Thicken sauce to your preference.
Return steaks to skillet and cook until just heated through. Check for doneness, if needed.
Add salt and pepper to taste.
Place steaks on individual plates and spoon sauce on top.
Serve immediately with your favorite side dishes.