Heat oil in saucepan; add shallots and cook for
3 minutes. Add beef
broth, wine, and brandy; reduce until thickened, about 5 minutes. Add
cream, reduce until 3/4 cup. Set sauce aside.
Melt butter in skillet, add garlic, saute 1 minute. Add spinach,
cook until wilted, tossing, about 2 minutes. Set aside.
In another skillet heat oil, add tenderloins and cook until desired
doneness. Divide spinach between 4 plates, top each with a filet. Add
sauce back to steak pan, stir in mustard and tarragon, add salt and
pepper to taste, pour over steaks.