Handfuls of fresh herbs and leafy greens plus fronds of fennel provide a depth of flavor in this summery salad. Tart cherries are quickly marinated in a simple sherry vinaigrette then mixed with the salad.
Stir together vinegar, lemon juice, a large pinch of salt, and a few grinds of pepper. Whisk in oil. Stir in cherries; let stand at least 5 minutes and up to 30 minutes.
Finely chop fennel fronds; mix with herbs. Toss greens with herb mixture. Gently mix in onions, radishes, and sliced fennel; add dressing and cherries, tossing to combine. Season with salt and pepper and serve immediately.