Preheat oven to 350 degrees. Heat a 12-inch non-stick saute pan over a high flame. Season the salmon fillets with salt and pepper. Add a small amount of oil to the pan and sear both sides of the salmon quickly, just a few seconds on each side, leaving the fish very rare. Remove the pan from the heat, and place the fish on a work surface. Wipe out the pan and reserve for later use.
Spread a 1/4-inch layer of Pesto evenly over 1 side of the fillet. Sprinkle the top of the pesto with a light, thin dusting of fresh bread crumbs. Carefully invert each fillet into the pan and place it over a medium flame. Toast the bread coating, adding tiny bits of butter to the pan that will melt into the salmon underneath. Once the bread is toasted (after about 1 minute), place the pan in the oven for about 3 minutes, just to heat the fish through.
To serve, mound 1/6 of the Steamed Spinach Leaves in the center of a warm dinner plate. Invert 1 salmon fillet onto the spinach, crust-side up, and ladle Citrus Soy Sauce around the sides. Place 1 orange segment on top of 1 grapefruit segment in the sauce at 3 different points on the plate.
For the Pesto: In the bowl of a food processor place, pine nuts, garlic, salt, and pepper. Add the basil and process again. With the motor running, add the oil in a stream slowly, scraping down the sides of the bowl occasionally. Add bread crumbs a little at a time, just enough to make pesto spreadable. Process and repeat until the pesto is the right consistency. Remove from food processor and set aside until ready to use.
For the Citrus Soy Sauce: In a non-reactive saucepan, saute the ginger in 1 tablespoon olive oil for 1 minute over medium heat. Add the shallot and garlic and continue cooking for 1 minute longer. Deglaze the pan with white wine, champagne vinegar, soy sauce, fish sauce, and all 3 fruit juices. Reduce the liquid volume down to 1 cup. Add the chicken stock, bring it to a boil, and cook another 3 minutes.
Strain, pushing on the solids to extract as much liquid as possible, and place the liquid into a blender or food processor. With the motor running on low, add the remaining olive oil in a slow stream until all the oil is incorporated. (Makes about 1 1/2 cups)
For the Steamed Spinach Leaves: Wash spinach thoroughly and drain, leaving some of the water clinging to the leaves. In a 12-inch saute pan over medium heat, saute the spinach in a small amount of olive oil until it is wilted, 1 to 2 minutes. Drain excess moisture, season with salt and pepper.
This recipe yields 6 servings.