Peel back the corn husks without removing husk or stem. Remove all of the corn silk. With husks pulled back, tie together with piece of husk. Grill over medium-high heat 10 minutes or until corn is tender and lightly charred to golden brown, turning occasionally. Cool slightly. Cut corn kernels off cob.
Mix lemon juice, liqueur, rocoto paste, cumin, garlic, sea salt and pepper in medium bowl until well blended. Refrigerate until ready to use.
Bring 1 cup water to boil in medium saucepan on medium heat. Gently stir in shrimp; cover. Steam 5 minutes or just until shrimp turn pink. Drain and rinse under cold water. Slice shrimp in half horizontally. Add shrimp to rocoto marinade; toss to coat well. Cover. Refrigerate 30 minutes.
To serve, arrange shrimp, corn and honeydew in shallow serving plates. Drizzle each with the rocoto marinade. Garnish with Fresno chilies and cilantro.