Chef Eric Ripert, of New York's Le Bernardin restaurant, shares his recipe for this spring delicacy.
Make the sauce: Place bacon in a medium skillet, and cook over high heat until bacon is golden and just crisp. Remove 2 tablespoons bacon, and drain on a paper towel-lined plate; set aside. Continue cooking the remaining bacon until very crisp but not blackened. Transfer to a fine sieve; discard bacon fat. Transfer crisp bacon to the jar of a blender.
Meanwhile, in a small saucepan, bring chicken stock to a boil over high heat. Add butter, piece by piece, whisking constantly until incorporated. Add the chicken-stock mixture to the blender, and blend on high speed until bacon is pureed. Season with salt and pepper. Set aside in a warm place until ready to serve.
Cook the shad roe: Preheat the oven to 400 degrees. Using a sharp knife, trim shad roe, and divide into 2 pieces, being careful not to tear the membrane. Pour flour into a shallow bowl, and season with salt and pepper; dust pieces lightly with the flour.
In a medium nonstick ovenproof saute pan, heat grapeseed oil over medium heat. Add shad roe, and cook until golden, 2 to 3 minutes. Turn, and transfer the saute pan to the oven until roe is cooked through, 3 to 4 minutes. Remove from saute pan, and set aside while preparing salad.
Make the salad: In a large bowl, combine vinegar, garlic, 1/4 teaspoon salt, and a pinch of pepper. Whisk to combine. Slowly add olive oil, whisking constantly, until combined. Add frisee and the reserved bacon; toss to combine.
To serve: Slice the shad roe crosswise on the bias into 1/2-inch-thick slices. Divide among four plates. Spoon the bacon sauce over, and serve immediately with the frisee salad on the side.