Add the extra virgin olive oil, red wine vinegar, honey, garlic powder, salt, and black pepper to a small bowl or jar. Whisk well, or seal the jar and shake, until the honey vinaigrette is smooth and emulsified.
Taste the dressing and adjust it if necessary. Add a little more honey when the peaches are tart or a small splash of vinegar when they are particularly sweet.
Wash the baby greens and dry them thoroughly. Slice the peaches into wedges and slice the cucumbers. Thinly slice the red onion, tear or chop the mint leaves, and roughly chop the walnuts.
Place the mixed baby greens in a large serving bowl. Scatter the cucumber, red onion, fresh mint, and walnuts over the greens.
Arrange the fresh peach wedges over the top. This keeps the delicate fruit from becoming crushed while assembling the salad.
Just before serving your Peach Salad, drizzle over some of the honey vinaigrette. Toss everything gently until lightly coated, adding more dressing only as needed. Serve immediately.