Preheat oven to 375°F. Cut six pieces aluminum foil, sized to enclose one fillet each.
Season fillets with Sazonador and paprika; place on foil pieces. Sprinkle each fillet with lemon juice, and top each with one lemon slice and one cilantro sprig. Fold and seal foil pieces to form packets, and place on baking sheet.
Bake fillets thirty minutes.
Meanwhile, heat olive oil in medium saucepan over medium-high heat. Add onions and garlic, and cook until tender, about five minutes. Add rice, and stir to combine; then, add 4 cups water and salt. Bring to boil for one minute, then tightly cover, reduce heat to a simmer (low heat) and cook for about twenty minutes or until water is evaporated.
Turn off heat and allow rice to sit, covered, for five minutes. Fold cilantro and parsley into rice. Serve rice alongside fish.
Garnish with lemon wedges and cilantro sprigs.