
Blend 1/4 cup of juice, lemongrass, garlic, cilantro, coconut milk, vegetable oil, and salt on high until liquified. Place contents in a glass container or a large freezer bag. Add chicken and mix until chicken is fully coated. Let marinade for 20 minutes to 8 hrs.
Meanwhile, remove skin from mangos and carefully chop into small cubes. Chop cucumber into a similar size. Add both mango and cucumber to a medium bowl. Add red onion, remaining juice, lime juice, and sea salt. Toss gently until combined.
* cooking time does NOT include marinade time of 20 minutes to 8 hours.