In a bowl, combine the seafood, mango, jicama, onion, cilantro and mint; gently mix in the Mango Dressing; season with salt to taste.
Gently fold in diced avocado.
Serve ceviche in avocado shells on a bed of shredded lettuce, if desired.
To make the Mango DressingIn a blender container, combine 1 cup cubed mango, 1 small stemmed jalapeño pepper, 1 small garlic clove, 1/4 cup orange juice and 1/4 cup orange preserves.
Process until smooth.
For a more traditional ceviche, marinate 8 ounces diced uncooked mahi-mahi (about 1 cup) with lime juice to cover (about 1/3 cup), combined with 1/4 teaspoon salt until fish has an opaque “cooked” appearance.