Rinse the jasmine rice under cold water until the water runs clear.

In a large pot, combine the rinsed rice, chicken broth, and water. Bring to a boil over high heat, then reduce the heat to low and cover. Simmer for 45 minutes, or until the rice is very soft and the mixture has a porridge-like consistency.

While the porridge is cooking, heat vegetable oil in a skillet over medium heat. Add garlic and ginger, sautéing until fragrant, about 2 minutes.

Add the prawns to the skillet and cook until they are pink and opaque, about 3-4 minutes. Remove from heat.

Once the porridge is done, stir in the cooked prawns, scallions, soy sauce, and sesame oil. Season with salt and white pepper to taste.

Serve hot, garnished with additional sliced scallions if desired.