In a large bowl big enough to hold all the ingredients, mix the lemon juice and olive oil together, adding salt and pepper and tasting. Slightly over salt your vinaigrette for now since it’s going to be covering a lot of kale.
Add the shredded kale to the bowl with the lemon vinaigrette and mix it with your hands, massaging it gently until all the leaves are covered.
Add the salmon, hazelnuts, cranberries, and blue cheese. Toss (we like the "cover the bowl with a lid and shake vigorously” method) until all ingredients are evenly distributed in the salad, then serve.