Seared White Fish with Greek Salad

For the salad: Peel the cucumber, halve lengthwise and cut into 1 cm (approximately 1/2 inch) thick slices. Rinse the tomatoes, core and cut into wedges. Peel the onions and slice into thin rings. Rinse the lettuce, spin dry and tear into small pieces. Toss the cucumber, tomatoes, onions, lettuce, parsley and olives in a bowl. For the vinaigrette: In a separate bowl, whisk the vinegar with the oil, and season with salt and pepper. Toss with the salad. For the fish: Drizzle the fish with lemon juice. Dredge in flour, removing the excess. Heat the butter in a skillet, add the fillets and cook until golden brown, about 2-3 minutes per side.