In a large pot, heat the sesame oil over medium heat. Add the diced onion, ginger, and grated lemongrass and cook for about 3 minutes, or until softened and translucent.

Add the Vietnamese curry powder, bay leaves, and lemongrass stalks. Give it a good stir for about 30 seconds.

Add the mushrooms and let them cook for about 4-5 minutes, allowing them to absorb the flavors and develop a nice texture.

Add the sweet potato, eggplant, and carrot. Sauté the vegetables well for a couple of minutes to seal them in and prevent them from getting soggy too quickly.

Add the vegan fish sauce and sugar, mixing everything well.

Pour in the coconut milk, ensuring that all the ingredients are well combined. Add the water and salt, keeping in mind that the fish sauce or soy sauce already contains salt. Let the curry cook until the vegetables are almost tender, about 10 minutes. Taste and adjust the salt as needed.

Stir in the green peas and let them cook for about 3 minutes, or until they are just tender but still bright green. Taste the curry and adjust the seasonings as needed, making sure to strike the perfect balance of flavors.

Serve the one-pot vegan Vietnamese curry hot, garnished with fresh cilantro, Thai basil, lime wedges, and/or sliced red chili, if desired. Enjoy with a side of steamed jasmine rice or crusty bread (banh mi) for a complete meal.