This fruit-filled dip is sweet, salty, and savory all at once.
To prepare mango: Hold mango with a paper towel (to avoid slippage). Using a vegetable peeler, remove skin and discard.
With a knife, slice off wide, flat part of fruit on both sides of pit. Trim flesh from pit (discard pit).
Place parts cut side down; slice in half horizontally. Cut crosswise into thin strips; cut strips lengthwise into pieces.
To make guacamole: In a medium bowl, combine avocados, mango, garlic, cilantro, lime juice, and serrano chile; season with 1/2 teaspoon salt. Fold gently, leaving texture chunky.
If not serving immediately, cover with plastic wrap, pressing it onto the surface to prevent discoloration; refrigerate up to two hours.