Heat vegetable oil in a pan over medium heat.
Add minced garlic, ginger, and lemongrass to the pan. Sauté until fragrant and softened.
Stir in the red curry paste and shrimp paste (if using). Cook for another 2-3 minutes until the paste is well combined with the aromatics.
In a large bowl, combine the ground pork with the cooked aromatics, red curry paste mixture, sliced red chilies, chopped cilantro, chopped mint leaves, fish sauce, lime juice, sugar (if using), and ground black pepper. Mix thoroughly until all ingredients are well combined.
If using sausage casings, soak them in water according to package instructions. Rinse and stuff the casing with the pork mixture, twisting at intervals to form sausages. Tie off the ends.
If not using casings, shape the mixture into patties or logs. Grill or pan-fry over medium heat until cooked through and nicely browned on all sides, about 6-8 minutes per side.
If using casings, grill the sausages over medium heat, turning occasionally, until cooked through, about 15-20 minutes.
Enjoy your meal!