Season and cook the chicken. Season the chicken tenders with salt and pepper. Add butter and oil to a large pan and heat to medium-high. Cook the tenders until browned and fully cooked. Set aside.
Cook the vegetables. In the same pan, cook the minced garlic clove and sliced mushrooms. Stir for a few minutes over medium heat until the mushrooms become tender.
Add the flour and spices. Now add the all-purpose flour, thyme, onion powder, salt, and pepper. Stir for about one minute.
Stir in the broth and simmer with cream. Bring the heat to medium-high and slowly pour in the chicken broth while mixing. Bring the sauce to a simmer and then pour in the heavy cream.
Simmer and add the chicken. Let it come to a simmer once again and add the cooked chicken back in. Serve.