COMBINE salad dressing and seasoned salt in a small bowl. Pulse pretzels in a food processor until pretzels are finely chopped, leaving some small pieces; this makes about 1 cup. Place in shallow dish.
SPREAD each side of fish with salad dressing mixture; coat with crushed pretzels. Heat 2 tablespoons oil in large nonstick frying pan over medium heat. Saute fish slowly, cooking 3 to 4 minutes per side (or until golden brown and internal temperature reaches 145 degrees F) adding additional oil if necessary. Keep fish warm.
WHISK apricot preserves, Dijon mustard and half-and-half together in a small saucepan over medium-high heat. Cook until sauce is creamy and thickens slightly. Serve sauce over fish. Garnish with fresh chopped parsley, if desired.