In a large saute pan over medium heat, melt 2 tablespoons butter with olive oil.
2
Add onions, mushrooms and cayenne pepper. Saute until onions are translucent and mushrooms are tender, about 8 minutes.
3
Add wine and reduce until it''s almost evaporated. Add chicken stock and simmer until reduced by one third. In a small bowl press together remaining butter and flour with fingertips until well blended, then slowly add to the sauce while stirring with a wooden spoon.
4
Simmer until sauce resembles loose gravy, about 5 minutes.
