Place 1/2 cup cashews in a food processor; process until smooth (about 2 minutes), scraping sides of bowl once. Add yogurt; process until well blended. Remove from processor; set aside.
Combine onion, juice, ginger, and jalapeño in a blender or food processor; process until finely chopped.
Combine coriander and next 4 ingredients (coriander through cloves) in a large zip-top plastic bag; add 1/2 teaspoon salt and chicken. Seal bag and shake to coat.
Heat oil in a large nonstick skillet over medium-high heat; add chicken pieces. Cook 4 minutes on each side or until done. Remove chicken from pan; keep warm.
Add onion mixture to pan. Reduce heat to medium; cook 3 minutes or until liquid evaporates, stirring frequently. Add 1/2 teaspoon salt and yogurt mixture to pan; cook 3 minutes or until heated, stirring frequently.
Spoon 1/2 cup yogurt mixture onto each of 6 plates. Top each serving with 3 chicken pieces. Sprinkle each serving with about 2 1/2 tablespoons pineapple, 1 teaspoon chopped cashews, and 1 teaspoon cilantro. Arrange 4 pita wedges on each plate.