Jellybear, I have made this recipe many times and looks like it's tailor-made for what you've got on hand:
ROASTED SURF ‘N’ TURF
2 lobster tails
1/ 2 tsp. salt
1/ 2 tsp. Old Bay seasoning
1 (3 lb.) whole beef tenderloin
1 Tbs. melted butter or margarine
1 1/ 2 tsp. lemon juice
6 slices bacon
1/ 4 cup finely chopped shallots
1/ 4 cup finely chopped green onions (scallions)
1 clove garlic, finely minced
1/ 2 lb. mushrooms, thinly sliced
1/ 2 cup butter
1/ 2 cup dry white wine
1 tsp. Worcestershire sauce (optional) or
1 tsp. chopped fresh or 1/ 4 tsp. dried tarragon (optional)
Place lobster tails, salt and seafood seasoning in a medium saucepan and cover with water. Bring to a boil; reduce heat and simmer 5 minutes. Remove from water and drain. Let cool until able to be handled. Carefully remove lobster tails from shells, keeping meat in one piece. Cut each piece of lobster meat in half lengthwise and set aside.
Cut a horizontal pocket through the center of meat to within ½ inch of opposite side of tenderloin, slicing the entire length of tenderloin. Carefully stuff lobster pieces, end to end, inside tenderloin. Combine the 1 Tbs. melted butter and lemon juice; Drizzle on lobster. Fold over tenderloin to resemble original shape and tie with butcher’s twine. Set aside.
Cook bacon in a skillet until slightly crisp; drain, reserving drippings. Crumble bacon; set aside.
Put beef in shallow pan and brush entire surface of meat with bacon drippings. Insert meat thermometer in center of roast so the point is right below the lobster, making sure it doesn’t go all the way through and touch the pan. Bake at 400 degrees for approx. 25 minutes or until thermometer registers 130 degrees (rare).
While roast is cooking, saute shallots, green onions, garlic and mushrooms in ½ cup butter. Add wine and Worcestershire sauce or tarragon (but not both). Simmer until roast is ready. To serve, remove twine and sprinkle top of meat with crumbled bacon. Serve sauce with sliced tenderloin.
Note: The roast can be stuffed earlier in the day and refrigerated (uncooked). Add a few minutes more cooking time if made ahead. The sauce can also be made ahead and reheated.