You can make this salad about 6 hours ahead if you’d like: to do so, just leave out the basil and greens and fold them in right before serving. While I didn’t use it this time around, I think this salad would be great with some creamy goat cheese and if you’re looking to amp up the protein, you could always fold in a few handfuls of your favorite beans or marinated tofu. And remember you’ll have leftover pickled onions, so be sure to save them for future sandwiches and salads. Once you get used to having them around, they make for a most beloved condiment.
Place onion in a small bowl. Bring vinegar, salt and sugar to a boil in a small saucepan, stirring to ensure they’re mixed well. Pour over onion slices and let stand for 30 minutes. Drain but reserve the pickling liquid. Roughly chop the onions and set aside.
Bring quinoa, 3 cups of water and a generous pinch of salt to a boil in a medium saucepan. Cover and reduce the heat; simmer for 10 minutes. Remove from heat and cover. Let sit for 15 minutes. Fluff with a fork and spread into large salad bowl to cool.
Place both ears of corn in a large pot of boiling water. Allow the water in the pot to come back to a boil, cover, and cook on low for 3-4 minutes or until tender. Remove from pot and set on a dry, clean surface to cool. Once cool enough to handle, slice the corn off the cob by balancing a flat end of the cob on a cutting board and using a downward cutting motion with a nice, sharp knife. This should yield about 1 1/2 cups corn kernels for the salad.
In a large salad bowl, toss together corn, tomatoes, arugula, 1 cup chopped onions (use more if you’d like), basil and chives. Add olive oil and 3 tablespoons of the reserved pickling liquid. Fold in quinoa and stir well. Season with salt and pepper and more pickling liquid if you’d like.