Consider this salad a great idea you can play with. In the summer, cut fresh sweet corn straight from the cob, no cooking required. I like to use Rancho Gordo Domingo Rojo kidney beans, cooked in advance and chilled, but a can of cooked beans of any kind is swift. The original salad calls for a bit of brown rice; I don’t include that, but you can. Fresh herbs are key to the bright flavor here. I always use cilantro and mint, sometimes basil too. Be absolutely sure to rinse the quinoa before cooking, to avoid bitterness.
In a small saucepan, combine the quinoa with 2 1/2 cups water and a teaspoon of kosher salt. Bring to a boil, then simmer, covered, until the quinoa is cooked, but not too soft and mushy, about 10 minutes (keep checking, tasting as you go). Pour off any excess water. Cool the quinoa completely; this can be done quickly by spreading the warm quinoa out on a sheet pan.
In another (or the same saucepan, rinsed), combine the lentils with 1/2 cup water and 1/4 teaspoon salt. Bring to a boil, then simmer until the lentils are al dente, and have not split, about 7 minutes. Rinse the lentils with cold water and drain.
If the shelled edamame is frozen, rinse with cool water and drain.
In a large serving dish, combine the quinoa, lentils, kidney beans, edamame, yellow pepper, and red onion.
Make the vinaigrette in a small bowl by slowly whisking the olive oil into the lemon juice, rice vinegar, and garlic. Season with dried mint, 1/4 teaspoon salt, and pepper.
Pour the vinaigrette over the salad and mix well to coat everything. Taste and adjust seasonings. Stir in half of the chopped herbs, then garnish the top of the salad with more chopped herbs. Serve immediately, or chill in the refrigerator for up to four days before serving.