Step 1) Preheat grill to medium heat or about 350°F.
Step 2) Place fish in a large resealable plastic bag or mixing bowl and set aside.
Step 3) Combine marinade ingredients in a blender or food processor and pulse 6 to 8 times or until well chopped. Reserve 1/4 cup of the marinade in a small bowl and set aside. Pour remaining marinade over fish, stir to coat and set aside to marinate for 10 to 15 minutes.
Step 4) Separate lettuce into 16 large leaves. Rinse and pat dry; cover and chill until ready to serve. Combine pepper strips, jicama and reserved marinade in a bowl and stir to coat.
Step 5) Spray grill with grill spray. Remove fish from marinade and discard marinade. Grill fish over Medium Direct heat for 2 to 4 minutes per side or until cooked through and fish flakes with a fork. Transfer cooked fish onto a plate and break apart into 16 equal portions.
Step 6) To assemble tacos, arrange chilled lettuce “cups”, open side facing up on a serving platter. Spoon grilled fish into each lettuce cup, add pepper/jicama mixture and serve immediately with lime wedges.