Place the aromatics on a large piece of cheesecloth, gather the edges to enclose, and tie with kitchen twine.
Prepare an ice-water bath in a large bowl for shocking the beans (which stops the cooking and preserves their color). Drop the fava beans into a large pot of boiling salted water until bright green and just tender, about 2 minutes. Lift out the beans with a slotted spoon (or a spider) and plunge into the ice-water bath. Once they are thoroughly cool, drain and peel off the tough outer skins.
Pour the wine into a large saucepan and bring to a boil, then reduce the heat and simmer for 1 minute (to cook off some of the alcohol). Add veal, water, and 1 teaspoon salt. Bring to a boil and skim the foam from the surface with a slotted spoon (veal produces more surface foam than other meats, so this step is important). Add herb sachet and reduce heat to a low simmer. Cook, uncovered, 1 hour, skimming the surface frequently. Add artichoke hearts to the pot, submerging them partially in the liquid. Cook until the artichokes and veal are tender when pierced with the tip of a sharp knife, 20 to 25 minutes more, adding peas during the last 3 minutes of cooking. Remove the sachet and squeeze out the liquid into the pot. Then strain the contents of the pot through a fine sieve into a bowl or large measuring cup, reserving veal, artichokes, and peas. You should have about 3 cups liquid.
Wipe out the pot and return it to the stove. First, make a roux by melting the butter over medium heat until foamy, swirling the pan to melt evenly, then whisk in the flour and cook, whisking constantly, 1 minute. Next, make a veloute by whisking the reserved liquid into the roux and bringing to a boil (again, always whisking), cooking until the mixture is smooth. (Classic culinary teaching would have you whisk cold stock into a hot roux, or vice versa, to prevent the sauce from forming lumps, but that isn't necessary as long as you whisk diligently.) Reduce heat and simmer 10 minutes.
Whisk together the egg yolk, if using, and heavy cream, then temper by gradually whisking in a cup of the veloute (this will allow the egg to gently heat so it doesn't curdle). Now whisk everything back into the pot and cook over gentle heat until the sauce thickens enough to coat the back of the spoon, 1 to 2 minutes. (If you prefer, omit the egg and whisk the cream directly into the veloute in the pan.)
Return the veal, artichokes, and peas to the pot along with the peeled favas and cook gently to heat through, stirring. Add lemon juice. Serve garnished with dill and parsley.