Bring a large pot of salted water to the boil. Add the pasta and cook according to package instructions, until al dente. Drain and keep 1 cup of the pasta cooking water.
Meanwhile, place a large, wide Dutch oven or pot on medium high heat. Add 2 tablespoons of olive oil along with the ginger, lemongrass, and garlic and stir for 30 seconds until fragrant. Add the tomato, and season with about ½ teaspoon of salt and black pepper and stir until the tomato is soft, about 2-3 minutes.
Next, add the curry paste and the sugar and cook until the tomatoes have fallen apart and the paste turns darker and starts sticking to the pot, 2 - 3 minutes. Add the coconut milk and vegetable stock stir to combine. Cover and cook for 5 minutes, to allow the flavors to meld.
Add the peas and cook just until they are warmed through, about 1 minute.
Add the pasta and toss to coat, adding some pasta cooking water if the mixture seems dry.
To serve, drizzle with olive oil, top with grated Parmesan and coriander leaves.
