Heat broiler with a rack 6 inches from heat source. On a foil-lined baking sheet drizzle the pineapple chunks and orange quarters with 1 tablespoon olive oil and season with salt and pepper. Toss to coat, then broil until charred in spots, 8 to 13 minutes. Transfer fruit to a bowl or plate.
While fruit is broiling, make the mojo. Place garlic, jalapeño, cilantro, orange zest, lime zest, lime juice, ground cumin, dried oregano, 2 tablespoons olive oil, and 1 teaspoon salt into a food processor and run until a coarse paste forms. Transfer mixture to a large bowl.
Pat chicken dry and season all over with salt and pepper.
Place the chicken thighs on the same foil-lined baking sheet. The leftover juices from the pineapple and oranges will create a nice, fruity flavor for the chicken. Coat chicken with remaining 1 tablespoon olive oil and broil until cooked through and charred in spots, 15 to 20 minutes (no need to flip). Once chicken cools slightly, slice chicken.
Add the charred pineapple and orange wedges to the mojo chicken and serve on a platter. Season to taste with salt and pepper, and garnish with cilantro sprigs and lime wedges, if desired. Serve with a side of rice.
Serve with rice, if desired.