Special equipment: spice grinder
Finely grind the coriander seeds and peppercorns together using a spice grinder. Season the trout with salt on both sides and with the spice blend on the presentation side only. Set aside and make the sauce.
Heat the creme fraiche in a small pot set over low heat. Add about 1/4 teaspoon salt and bring to a simmer. Add the trout roe, shallots, white wine, finger lime, Meyer lemon and 1/4 teaspoon black pepper. Stir together. Remove from the heat and set aside.
Add 1 tablespoon vegetable oil to 2 cold, large, non-stick saute pans and place 2 pieces of trout in each pan, presentation-side down. Start the fish in a cold pan but raise the heat to medium and cook for 2 minutes, or until a nice crust is formed. Flip the fish and cook for 10 seconds, just to heat the other side. Remove the fish from the pans and set on a cutting board.
In a mixing bowl, combine the extra-virgin olive oil, lime juice and a little salt and pepper. Add the salad greens and toss to coat with the oil mixture. Warm the sauce over low heat. Slice the fish into thin slices and fan on the outer part of each of 4 plates in a circle. Place about 1/2 cup of the salad greens in the center of each plate. Spoon the creme sauce over the fish, making sure to get the trout roe, finger lime and Meyer lemon from the bottom of the pot. Serve immediately.
Finger limes are a type of citrus fruit native to Australia. They are cylindrical, sometimes slightly curved and somewhat resemble a gherkin. Its flavor is a combination of lemon and lime with green and herbaceous notes. When the fruit is cut in half, the juice vesicles, which are under pressure, can ooze out. The translucent greenish-white or pinkish vesicles in finger limes are round and firm, and pop on the tongue like caviar. They are available online and in specialty markets. Both the texture and the flavor of the finger limes play a part in this recipe, but if you can't find finger limes, you can substitute 2 teaspoons key lime juice to get a similar flavor. Tasmanian Sea Trout is a beautiful, orange-fleshed fish that is becoming more available, but if you have a hard time finding it you can substitute wild salmon. Smoked trout roe is available online and in specialty markets.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.