Coat a large nonstick saute pan with cooking spray.
Coat tilapia with blackening spice and cook over medium-high heat until fish flakes with a fork—about 2 to 3 minutes per side. Remove from pan and repeat with remaining filets.
Slice each radish in half and then thinly slice each half into 1/2 moons. Combine cucumbers, radishes, red pepper, scallions, cilantro, lime juice and olive oil in a medium bowl.
Scoop on top of the fish and serve.
Chop up tomatoes and add them to the cucumber radish salsa, top with fresh scallions, or serve over a bed of oven roasted onions. Onions contain chromium, which helps with blood sugar regulation, the green tops of the scallions are rich in Vitamin A, and tomatoes are high in antioxidants and lycopene, and are heart healthy- they have been shown to help lower cholesterol!