Step 1: In a medium pot, bring the vegetable broth and the reserved green tops of the lemongrass to a simmer. Keep warm over low heat.
Step 2: Preheat your oven to 400°F (200°C). Toss the asparagus with a little olive oil, salt, and pepper. Roast for 8-10 minutes until tender-crisp, then set aside.
Step 3: In a wide heavy-bottomed pan, heat the olive oil over medium heat. Add the shallots and cook until translucent, about 3 minutes.
Step 4: Add the minced lemongrass and garlic to the pan, sautéing for another minute until fragrant.
Step 5: Stir in the Arborio rice, ensuring every grain is coated in oil. Toast for 2 minutes until the edges of the rice look translucent.
Step 6: Pour in the white wine to deglaze the pan, stirring constantly until the liquid is fully absorbed.
Step 7: Add the warm broth one ladle at a time, stirring frequently. Wait until the liquid is almost completely absorbed before adding the next ladle. Continue until the rice is creamy and al dente (about 18-22 minutes).
Step 8: Remove the pan from heat. Gently fold in the roasted asparagus, butter, lemon zest, and half of the fresh basil.
Step 9: Season with salt and pepper. Garnish with the remaining basil and serve immediately.