How to Make It
In a small bowl, whisk 7 1/2 tablespoons of the olive oil with the sherry vinegar. Season with salt and pepper.
Heat the remaining 1 1/2 tablespoons of olive oil in a large skillet. Add the onion and cook over moderate heat, stirring, until softened and just beginning to brown, about 7 minutes. Add the shrimp, mint, raisins, cumin and a pinch each of salt and pepper and cook, stirring, until the shrimp are pink, about 7 minutes.
In a large bowl, toss the mesclun with the dressing and mound on 10 plates. Scatter the shrimp over the salads.