Measure the barley into a strainer and rinse with cold water. Transfer the rinsed barley to a medium saucepan. Add the water and ½ tsp kosher salt. Cover and bring to a boil over high heat. Once boiling, reduce the heat to low and cook at a low simmer for 40 to 45 minutes until the barley is tender. Allow the barley to cool completely before assembling the salad.
To toast the hazelnuts, bake the nuts at 350°F for 5-7 minutes until they smell toasted. You can check if the nuts are toasted by cutting one in half; the inside of the nut should be lightly browned. To peel the hazelnuts, wrap the warm nuts in a tea towel and rub them together. The friction will remove most of the skin. This can damage or discolour the tea towel so choose one that you don’t mind getting a bit dirty or line the tea towel with a layer of paper towel first. Roughly chop and set aside.
In a small bowl, combine the grainy mustard, honey, apple cider vinegar, remaining ½ tsp kosher salt, and pepper. Whisk together. Slowly add the light olive oil, whisking constantly. Keep whisking until the dressing comes together and is fully emulsified. Stir in the chopped fresh dill.
To assemble the salad, pour about half of the vinaigrette over the cold barley, tossing to coat well. In a separate bowl, dress the baby kale with some of the vinaigrette, tossing to coat. In a serving bowl, layer the barley and baby kale with the hazelnuts and blueberries, tossing together lightly. Drizzle any remaining vinaigrette over the salad and top with a sprinkle of hazelnuts and blueberries. Enjoy!
Notes
*You can substitute with chopped regular kale instead. I recommend lightly massaging some of the dressing into the kale to tenderize it before mixing with the salad.