Slice mushrooms; to pan, add mushrooms, white onion and garlic; cook until onion browns, 5 to 7 minutes. Add wine and simmer 3 ... stirring constantly, until sauce is thick enough to coat the ...
Pour in the wine and stir in the chopped thyme leaves, then leave to simmer for 5-6 minutes, or until the liquid has thickened. Pour the mushroom and red wine sauce over the steaks and serve.