In a small saucepan, bring water and salt to a boil. Add buckwheat groats, reduce heat, cover and cook until all water has absorbed, about 10 minutes.
Remove lid, delicately separate the grains with a fork and allow to cool for at least 30 minutes. You can also cook your buckwheat groats the previous day and let them cool overnight.
While buckwheat if cooling, shell the fava beans and cook them in a steamer for 3-4 minutes, or until fava beans are tender but still somewhat firm. Remove from heat and set aside. You COULD peel them if you wanted to, but that is completely optional.
Add all the ingredients of the vinaigrette to a small blender or food processor and process until smooth and creamy. Set aside.
Add all ingredients, including vinaigrette to a large mixing bowl and mix until well combined.
You can serve this immediately or refrigerate overnight.