Beef Tenderloin with Tarragon Mayonnaise

1/8 c. olive oil
1 11/4 pound. tenderloin
1 Shallot,finely minced
1/6 c. white wine vinegar
1/8 cup dried tarragon
1/4t. salt
ground peppere
1 egg yolk
11/2 t. Dijon
1/2 t. white wine vinegar
2/3 c. canola oil

Roast tenderloin at 400F about 35 minutes, test for doneness. 125F, below rare. Chill. Cut on diagonal into 1/4inch slices. Serve with toothpicks and pass sauce.

Combine Shallot, 1/6 cup vin. tarragon, salt and pepper in a small non-aluminum saucepan and simmmer till vinegar is reduced by half and tarragon is softened, about 5 min.
Cool slightly. Combine yolk, mustard, vinegar and 2 Tbs oil; whip until mixture begins to thicken. With processor, blender or mixer runnigh, slowly pour remaining oil in a thin stream (will thicken) and add tarragon mixture.
Blend quickly. Taste and adjust seasoning. Chill before serving.

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