Cut the potatoes about 3/4 inch wide by 3/4 inch deep and 1 inch long.
Carve each piece into the shape of an olive (relatively uniform pieces will cook evenly).
Melt the butter over medium-low heat in a large nonstick saute pan.
Add the potatoes and saute for about 15 minutes, or until light golden brown and cooked through.
Season with salt and pepper to taste, and toss with the parsley.
TO PREPARE THE BEARNAISE SAUCE:.
Combine the vinegar, wine, shallots, 2 teaspoons of the tarragon, and peppercorns in a small saucepan and bring to a boil.
Lower the heat to a simmer and reduce the liquid by half.
Let cool until lukewarm.
Transfer to the top of a double boiler set over briskly simmering water, and add the egg yolks and lemon juice, whisking constantly until the mixture thickens to the consistency of heavy cream.
Add the butter and whisk until the sauce thickens again.
Season with salt and pepper and strain the sauce into a clean saucepan; thin with a little water if necessary.
Keep warm, and just before serving, stir in the remaining tarragon and the chervil.
TO PREPARE THE CHATEAUBRIAND:.
Preheat the broiler.
Season the steak with salt and pepper, and place in a shallow bowl.
Combine 1 tablespoon of the olive oil with the garlic and spread over the entire steak.
Heat the remaining 1 tablespoon on olive oil in a cast-iron skillet over medium-high heat.
Sear the steak on all sides for about 4 minutes, or until browned.
Transfer to the lowest rack of the broiler and broil for about 10 minutes longer for medium-rare or 12 minutes longer for medium.
Remove from the broiler and let rest about 5 minutes before cutting.
FOR THE LOBSTER:.
Remove the shell from the lobster tail meat and season the lobster with salt and pepper.
Combine the butter and garlic and spread on the lobster meat.
Place the lobster on a broiler pan and broil on the lowest rack of the broiler for about 7 minutes, or until the lobster is just cooked through.
Spoon about 2 tablespoons of bearnaise sauce onto the center of warm dinner plates and spread out to make a 3-inch circle.
Cut the Chateaubriand in half and place it cut side down onto the béarnaise sauce.
Place the lobster beside the Chateaubriand so that it curls around the steak.
Arrange the potatoes on the other side of the steak.
Spoon more béarnaise sauce over the steak and along the length of the lobster.
Drizzle extra béarnaise around the edge of the plate, if desired.
If you are looking for wines to match the food, try either a Sauvignon Blanc from California or a Pouilly Fume from the Loire Valley in France. If you prefer red wine, choose a West Coast Pinot Noir or a French Burgundy.