Crush first 3 ingredients with a mortar and pestle (or place in a heavy-duty plastic bag, and crush with a meat tenderizer). Transfer to a large bowl; add sugar, kosher salt, and lemon juice, stirring until sugar and salt dissolve. Stir in oil and next 4 ingredients.
Cook shrimp in boiling water to cover 1 to 2 minutes or until pink. Drain; add to marinade, tossing to coat. Cover and chill 8 hours or overnight. Store 3 to 5 days in refrigerator, stirring occasionally. (The flavor gets more pronounced with time.)