In a small bowl, stir together the mint, parsley, 1 teaspoon of garlic, and lemon zest. Set aside.

In a medium saucepan, combine the broth and water. Bring to a simmer, then reduce the heat to low to keep it warm while you prepare the risotto.

In a large pot over medium heat, melt 1 tablespoon of butter. Add the asparagus, 1/8 teaspoon of salt, and 1/8 teaspoon of pepper. Cook for 4 minutes, stirring often until the asparagus is just tender. Stir in the peas and cook for 1 more minute. Transfer the vegetables to a plate and set aside.

In the same pot, melt 3 tablespoons of butter over medium heat. Add the leeks along with the remaining 1/2 teaspoon of salt and 1/2 teaspoon of pepper. Cook for 3 minutes, stirring frequently, until softened. Add the remaining 2 teaspoons of garlic and cook for 1 minute. Stir in the rice and cook for 3 minutes, stirring often, until lightly toasted.

Pour in the white wine and stir frequently for about 3 minutes, until the wine is fully absorbed.

Add 4 cups of the warm broth mixture to the pot. Reduce the heat to medium-low. Cover and simmer for 20 minutes, stirring every 5 minutes, until most of the liquid is absorbed.

Add 1/2 cup of the remaining warm broth and stir gently for 3 minutes, just until the risotto is creamy. Remove from heat. Stir in the Parmesan cheese, then cover and let sit for 5 minutes. Uncover and stir in the lemon juice and the remaining 1 tablespoon of butter.

Fold the asparagus and peas back into the risotto. If the texture is too thick, stir in the remaining 1/2 cup of water to loosen it slightly.

Sprinkle the reserved herb and lemon mixture over the top and serve hot.