Bring chicken broth (or water), olive oil and salt to boil in a saucepan.
Add couscous to pan.
Cover with lid and remove from heat. Let sit for 5 minutes. After 5 minutes, remove lid and break up couscous so no clumps remain.
Wash, dry and chop lettuce, set aside in refrigerator.
Cook corn, rinse with cool water. Cut corn off cob and place in refrigerator to cool completely. If using frozen corn, do not thaw, when ready to assemble salad take bag of corn from freezer and use in salad.
Make dressing by mixing all ingredients in blender or by using a hand immersion blender. Refrigerate.
Chop lettuce into bite size pieces. Add lettuce and rest of salad ingredients into bowl. Just before serving, drizzle dressing (I only use about 1/2 ) and toss. You may serve additional remaining dressing on