Heat medium skillet over medium-high heat. Add chiles. Toast, turning once, until fragrant, about 2 minutes. Transfer chiles to small bowl; cover with 1 cup boiling water. Let soak, flipping occasionally, until softened, about 20 minutes. Meanwhile, in same skillet over medium-high heat, toast garlic cloves until paper turns golden brown on all sides, about 7 minutes; set aside until cool enough to handle. Peel garlic. Transfer chiles and their liquid, garlic, onion, naranja agria, oil, brown sugar, Sazón and 1 tsp. Adobo to blender. Puree until smooth, about 2 minutes. Reserve ¾ cup chile marinade for gravy; cover and refrigerate. Set remaining chile marinade aside.
Place turkey in non-aluminum container large enough to hold turkey and marinade. Season cavity and skin of turkey with Adobo. Rub turkey all over with reserved chile marinade, including cavity, until completely coated; cover and refrigerate at least 12 hours, or up to 48 hours. Bring turkey to room temperature 1 hour before roasting.
Heat oven to 450°F. Set turkey on rack set inside roasting pan; brush turkey with marinade from bottom of container until coated; discard remaining marinade. Tie turkey legs together with kitchen twine, tuck wings behind back and tuck excess skin from neck into top cavity. Pour 2 cups water in bottom of roasting pan. Lightly season turkey with Adobo. Roast turkey 30 minutes. Reduce heat to 350°F. Baste turkey. Add 1 cup water to bottom of roasting pan; loosely cover turkey with foil; rotate pan. Roast, basting occasionally, until skin is dark golden brown and crisp and turkey is cooked through (quick-read thermometer registers 165°F when inserted into thickest part of thigh without touching bone), 3 hours 15 minutes-to-3 hours 45 minutes, adding water in 1 cup measurements if pan becomes dry. Carefully remove rack from pan; loosely tent turkey with foil to keep warm before carving (at least 30 minutes and up to 1 hour).
Straddle roasting pan between two burners over medium-heat; bring drippings to simmer. Add port. Cook, scraping up browned bits from bottom of pan, until port mixture boils. Carefully strain liquid through fine-mesh sieve into large measuring cup; discard solids. Skim off and reserve fat from measuring cup. Add enough chicken bouillon mixture to pan juices to equal 3 cups liquid total.
Add 6 tbsp. reserved fat (if there is less, add corn oil) to medium saucepan over medium-high heat. Using whisk, add flour and whisk occasionally until flour turns light golden brown and begins to bubble; about 1 minute. Whisk in reserved chile marinade; cook until beginning to caramelize, about 3 minutes. Add pan juice mixture. Cook, whisking vigorously to prevent clumps, until liquid comes to boil. Reduce heat to low. Simmer, whisking occasionally, until gravy is thickened and smooth, about 5 minutes. Season with Adobo, if needed.
Transfer turkey to cutting board; carve. Arrange turkey on serving platter. Transfer any juices from cutting board to pot with gravy. Serve turkey with hot gravy.