To make the sauce:
In a small saucepan, bring 1 cup of water to a boil over medium-high heat. Add a pinch of salt, the parsley leaves, and the tarragon, lovage or fennel leaves. Boil for 1 min. Turn off the heat, add all but 3/4 cup of the peas, and let stand for 5 minutes. Purée the mixture in a blender at high speed until smooth, about 1 minutes. Using a rubber spatula, force the purée through a sieve. Season to taste with additional salt and white pepper. You should have about 1 cup of sauce.
To make the rice:
Put the stock in a medium saucepan and bring to a simmer over medium-low heat. In a wide pot over medium heat, melt the butter. Add the leek whites, cooking until they start to soften, 3 to 4 minutes. Add the rice and cook, stirring frequently, until the grains are completely coated with butter, about 1 min. Add the wine and simmer until absorbed. Add 2 cups of the stock and cook at a lively simmer, stirring occasionally, until it has been absorbed, about 3 minutes. Add 1/2 tsp. salt and then add another cup of stock. Cook, stirring occasionally, until the liquid has been absorbed. Add 1/2 cup stock, now stirring more frequently. Once the liquid is absorbed, test the rice for doneness: it should be tender, but with a bit of bite. If the rice needs more cooking, add another 1/2 cup stock. When the rice tastes nearly done, stir in the pea-parsley sauce and the reserved 3/4 cup peas. Raise the heat and cook briskly, stirring all the while until the rice is done and most of the sauce has been absorbed. Remove the pan from the heat, stir in the crème fraîche and the Parmigiano-Reggiano. Add the chervil or tarragon, season with a few grinds of pepper, and serve.
nutrition information (per serving):
per first course portion;
Photo: Scott Phillips