In a large saucepan, heat the coconut oil and olive oil over medium-high heat. Add the onion, lemongrass and ginger and cook until the onion begins to soften and turn translucent, 5 to 7 minutes. Reduce the heat to medium-low, add the rice and cook for 1 to 2 minutes, stirring to thoroughly coat the rice with oil. Stir in the sweet rice wine and cook until it is completely absorbed. Now begin adding the vegetable broth, about 1/2 cup at a time, allowing each 1/2 cup to be fully absorbed before adding another. Repeat in this way until about 1 cup of the broth remains.
Stir the asparagus, basil and truffle salt into the rice. Continue cooking, adding the remaining broth as before, until the broth is completely gone and the rice has become tender and very creamy. (The entire cooking process should take 35 to 40 minutes.) Stir in the coconut milk and cook until fully absorbed, another 1 to 2 minutes. Season with salt and serve immediately.