1 1/2 cups quinoa (any color), rinsed well
1 medium onion, sliced 1/4-inch thick
1/2 cup apple cider vinegar
3 tablespoons sugar
4 teaspoons kosher salt, plus more for seasoning
2 large ripe firm peaches, cut into 1/2-inch pieces
1/2 bunch mustard greens, thick stems trimmed, roughly chopped
2 cups small cherry tomatoes, halved
1/4 cup olive oil
Freshly ground black pepper
- Bring quinoa and 3 cups water to a boil in a medium saucepan. Season with salt. Cover, reduce heat, and simmer for 15 minutes. Remove from heat and let sit 15 minutes. Fluff with a fork and let cool.
- Place onion in a small bowl. Bring vinegar, sugar, and 4 teaspoons salt to a boil in a small saucepan, stirring to dissolve sugar and salt. Pour over onion and let stand 20 minutes. Drain and reserve pickling liquid
- Toss pickled onion, peaches, greens, tomatoes, oil, and 3 tablespoons reserved pickling liquid in a large bowl; season with salt, pepper, and more pickling liquid, if desired. Fold in quinoa.
- Serve chilled or room temperature.