Combine the basil, cilantro, 1/4 cup coconut milk, the fish sauce, soy sauce, coriander, cumin, sugar, garlic, chile, ginger, lemongrass, lime juice, shallot and some black pepper in a food processor. Blend until a paste forms.
Heat the canola oil in a large pan over medium-high heat. Add the curry paste and stir-fry for 1 minute. Add the stock and kaffir lime leaves and bring to a boil. Turn down the heat to medium and simmer for 10 minutes. Add the bell pepper, eggplant and the remaining 1/2 cup coconut milk and cook until the vegetables are tender, 15 to 20 minutes.
Meanwhile, cook the noodles in salted boiling water until al dente. Drain.
Fill a big bowl with the noodles and cover with the spicy green curry sauce.