Prepare lemon Dijon vinaigrette. Whisk to combine mustard, olive oil, and 3 T. lemon juice together in a small bowl. Season to taste with sea salt and black pepper. Set aside.
Season the fresh salmon fillets with salt and pepper to taste. Spoon 1 tablespoon of Dijon citrus vinaigrette over each piece of salmon. Let rest for 5 minutes.
Meanwhile, arrange lettuce, avocado, radishes, dill, and cucumber in a large bowl. Set aside.
Heat one tablespoon of olive oil in a stove-top grill pan over medium-high heat. Place the salmon on the pan and eventually adjust to medium heat. While the salmon cooks, make sure to turn every 3-5 minutes per salmon skin-side to get the desired degree of doneness.
Set the hot pan aside then place the salmon filet on each salad plate.
Add a few dollops of salad dressing to each salad.
Sprinkle each salad with blue cheese and sesame seeds.
Lightly drizzle the salmon steaks (and salad) with the remaining dressing, if desired. Enjoy!