Corn, Shrimp and Quinoa Salad

This recipe is from the Sunflower Farmers Market website. What?! You haven't been to Sunflower Market? And you haven't been to Sunflower Market's website? Thanks to Heather's urging, I have--and so should you. It's great. So is this recipe. It was perfect on a warm, spring day like today.
Supersweet Corn, Shrimp and Quinoa Salad
3 c. cooked quinoa**, or prepared couscous
1 can (15 oz.) black beans, drained and rinsed
3 c. fresh supersweet corn kernels, 4 medium ears (I used a can of sweet corn, which I know could never compare to fresh supersweet corn, but it's still winter you know...)
1 c. seeded and diced (1/4 in.) red and green sweet bell pepper
1/2 c. chopped red onion, soaked in hot water for 5 min. and drained
1/4 c. thinly sliced scallions (white part and 1 inch of the green)
8 oz. good-quality salad shrimp, or 2 cups cooked chicken, smoked turkey, or imported boiled ham cut into 1/2 inch cubes (optional)
1/4 c. minced fresh cilantro leaves
1/3 c. extra virgin olive oil
3 Tbsp.cider vinegar
1 Tbsp. Dijon mustard
3/4 tsp. salt
1/2 tsp. freshly ground black pepper
2 tsp. of sugar
(I also squeezed some fresh lime juice over the salad--it needed a little more acidity)
**Prepare with 1 c. uncooked quinoa; cook according to pkg. directions.

1. Add prepared quinoa to a large mixing bowl. Add the beans, corn, bell peppers, onion, scallions, and shrimp (if using) and toss to combine well.
2. To make the vinaigrette, in a sealable container, combine all the ingredients and shake for a few seconds, until the mixture thickens.
3. Toss the salad with the vinaigrette (use a little less if not using shrimp). Add salt to taste. Cover and refrigerate until needed.
4. Just before serving, toss the salad with the cilantro. Garnish with halved cherry tomatoes, or serve on a bed of greens, if desired.