• 4 medium red beets , trimmed
• 1/2 cup red wine vinegar
• 1 1/2 teaspoons salt
• 2 medium red onions , each sliced into 1/2-inch-thick slices
• 2 tablespoons extra-virgin olive oil
• 1/4 teaspoon freshly ground pepper
• 6 cups mesclun
• 6 ounces Manouri or other mild goat cheese , diced
• 2 tablespoons red wine vinegar
• 1 tablespoon olive brine (from jar of Kalamata olives)
• 1 teaspoon honey
• 1/2 teaspoon dried oregano (preferably Greek), crushed
• 1/4 teaspoon salt
• 1/8 teaspoon freshly ground pepper
• 1/4 cup extra-virgin olive oil

In a large saucepan, combine beets, vinegar, 1 teaspoon salt, and enough cold water to cover beets by 2 inches; bring to a boil. Reduce heat and cook until tender, 40 to 45 minutes. Cool beets in cooking liquid; peel. Using a handheld slicer, cut beets into 1/8-inch-thick slices. Set aside.

Meanwhile, heat a grill or a grill pan. Brush both sides of onion slices with olive oil; sprinkle with pepper and remaining 1/2 teaspoon salt. Grill onions over medium heat until evenly charred and tender, 2 to 3 minutes per side.

In a small bowl, whisk together vinegar, brine, honey, oregano, salt, and pepper. Gradually add oil, whisking in a thin, steady stream until blended.

Arrange 1 cup greens and 1/4 cup cheese on each of 6 plates. Divide the sliced beets and grilled onions equally among the plates, and drizzle with vinaigrette.