How to Make It
Place chicken thighs in a large ziplock plastic freezer bag. Process orange juice, lime juice, garlic, salt, minced cilantro, and achiote paste in a blender until smooth. Pour over chicken; seal bag, and turn to coat. Chill 3 hours.
Preheat grill to medium (350°F to 450°F). Place pineapple slices on oiled grates, and grill, uncovered, until slightly charred, 2 to 3 minutes per side. Chill 30 minutes.
Meanwhile, remove chicken from marinade; discard marinade. Place chicken on oiled grates, and grill, covered, until a thermometer inserted in thickest portion registers 165°F, 6 to 7 minutes per side. Remove from grill; cover with foil while pineapple chills.
Dice grilled pineapple; toss with cilantro leaves and jicama.
Slice chicken, and divide among warmed tortillas; top tacos with pineapple mixture. Serve with limes and salsa.