Season salmon with 2 teaspoons of Dijon, 1/2 teaspoon dried parsley, 1/4 teaspoon salt and black pepper.

Adjust the oven on the second rack. Broil salmon for 6 to 7 minutes, until cooked through.

In a large bowl, combine red onion with olive oil, apple cider vinegar, remaining Dijon, garlic powder, parsley, salt, and pepper. Let sit for about 5 minutes.

Add cherry tomatoes, avocado, and toss. When ready to serve, add chopped lettuce and cabbage, finish with remaining vinegar, and adjust salt and pepper as needed.

Divide the salad among 4 bowls and top each with a cooked salmon fillet.