Melt one Tbsp butter in a pan and sauté mushrooms; set aside.
In a medium saucepan melt two Tbsp of butter and stir in the flour until dissolved. Add chicken stock, cream, garlic and pepper, stirring constantly cook until sauce thickens. Do not boil. Once thickened reduce heat, cover, and cook 2 more minutes.
Add picante sauce, blackening seasoning and saut?ed mushrooms, heat through. Hold warm until ready to serve.
Serve over grilled or broiled fish.Makes 4 servings. Source: