In small bowl, whisk together pomegranate reduction, garlic, oil, sugar, salt and serrano pepper.
Add prawns to marinade. Let sit at room temperature for no longer than 20 minutes.
Place cast iron skillet over medium heat, and pan fry prawns for 2 minutes per side. (Alternative: grill prawns on barbeque at medium heat for 2 minutes per side.)
Transfer to serving plates, garnish with cilantro, lime wedges and pomegranate seeds (optional).