Combine mustard, vinegar, honey, 1 teaspoon oil, and 1/8 teaspoon salt in a small bowl; stir with a whisk. Set aside.
Combine remaining 1 tablespoon olive oil, lemon juice, kosher salt, and pepper in a large zip-top plastic bag.
Add fish to bag; seal. Marinate in refrigerator 10 minutes.
. While fish marinates, place potato and whole eggs in a large saucepan or Dutch oven; cover with water. Bring to a boil. Reduce heat, and simmer 10 minutes.
Remove eggs and plunge into cold water. Cook potato 5 minutes; add green beans. Simmer 5 minutes or until vegetables are tender.
Remove potato and beans, and plunge into cold water; drain. Peel eggs, and slice each into 6 wedges; set aside.
. Prepare grill.
Place fish, skin sides down, on grill rack coated with cooking spray, and grill, covered, 10 to 12 minutes or until fish flakes easily when tested with a fork.
Remove skin from fish, and cut fish into chunks.
Combine spinach, olives, tomato, and onion in a large bowl; add vinaigrette, potato, and beans, and toss to combine. Arrange salad evenly on plates, and top evenly with fish and eggs.