Preheat the grill to medium-high.
Combine all the spices in a small bowl. Brush both sides of fish fillets or chicken breasts with oil. Rub 1 side of the fish fillets or chicken breasts with the rub and grill, rub side down, until golden brown and a crust has formed, about 4 minutes. Flip over and continue cooking for 3 to 5 minutes.
Click here for Bobby's Buttermilk Southwestern Grilled Chicken.