Whisk together orange zest, orange juice, olive oil, Dijon mustard, honey, garlic, salt, pepper and hot pepper flakes. Reserve half of the dressing; set aside. In resealable plastic bag, combine remaining dressing with salmon; refrigerate for at least 10 minutes or up to 1 hour.
In pot of boiling salted water, blanch snap peas for 1 to 2 minutes or until tender-crisp. Refresh under cold running water; drain and pat dry with paper towel. Toss snap peas with reserved dressing, then stir in oranges, radishes and red onion.
Meanwhile preheat grill to medium-high heat; grease grate well. Grill salmon for 4 to 6 minutes per side or until fish just starts to flake. Divide salad among 4 plates; top with salmon.
Tip: Add 1 ripe avocado (peeled, pitted, and sliced) and chopped toasted walnuts, if desired.
