Wash your green beans thoroughly and trim the ends.
Bring a large pot of water to boil. Add in salt.
Add the green beans, and blanch them for about 4 minutes. Drain and cover with ice cold water to stop them from cooking. Pat dry and set aside.
Preheat oven to 350°F.
In a large braising pan, heat 2 tablespoons of butter and a little canola oil over medium heat. Add in the mushrooms and thyme and cook until mushrooms are slightly tender.
Add the minced garlic, and gently stir to cook for about 30 seconds. Be careful not to burn the garlic.
Add in the flour and toss with the mushroom mixture until evenly coated. Cook for about 1 minute.
Pour in the chicken stock, while scraping up any bits on the bottom of the pan.
Pour in the heavy cream, stirring or whisking constantly to avoid any lumps. Season to taste with kosher salt, blackpepper, garlic powder and smoked paprika. Once the sauce begins to thicken after about 3 to 5 minutes add in parmesan cheese and turn off the heat.
Add blanched green beans to the mushroom cream sauce in an even layer and top with the fried onion strings.
Place in the oven and heat until the onions get nice and golden on top. Enjoy!