• Zest and juice the lemon, keeping the zest and juice separate. Set aside the juice for the vegetables.
• Coarsely chop the pine nuts. Alternatively, using the bottom of a bowl or cup, lightly crush the pine nuts.
• Strip the parsley leaves from the stems; coarsely chop the leaves.

In a small bowl, stir together the lemon zest, pine nuts, and parsley. Season to taste with salt and pepper.

Prep and cook instructions are almost identical for both fish options.

• Pat the fish dry with a paper towel; season lightly with salt and pepper.

In a large frying pan over medium heat, warm 1 to 2 teaspoons oil until hot but not smoking. Working in batches if needed, add the fish (skin side down for the trout) and cook without turning until lightly browned and almost cooked through, 3 to 4 minutes for sole, 2 to 3 minutes for trout. Transfer to a plate (discard the trout skin if desired). Add more oil between batches if needed.
Top 1 piece [2 pieces] of fish with the stuffing, spreading in an even layer; using a spatula, top the stuffing with the remaining fish, browned side up. Return the pan to medium heat and continue cooking until the fish is cooked through, 2 to 3 minutes. Transfer the fish to a cutting board and cut in half crosswise. Wipe out the pan.
While the fish cooks, prepare the vegetables.

• Cut away the cores from the tomatoes; coarsely chop the tomatoes.
• Rinse the white beans.
• Coarsely chop the olives.

In the same pan used for the fish, warm 1 to 2 teaspoons oil over medium-high heat until hot but not smoking. Add the kale and tomatoes, season with salt and pepper, and cook, stirring occasionally, until the kale is wilted and the tomatoes start to break down, 2 to 3 minutes. Add the beans and cook, stirring occasionally, until warmed through, 2 to 3 minutes. Remove from the heat, stir in the lemon juice and olives, and season to taste with salt and pepper.

Transfer the fish and vegetables to individual plates and serve.