This is a wonderfully strange and delightful recipe that requires intimate knowledge of the main ingredient.
You braise new spring peas in a little liquid for a comparatively long time. This means the tiniest spring peas would be overdone, but fully mature summer peas lack the sweetness of their adolescent kin, and it's that sweetness that so perfectly complements the peculiar choice of lettuce as a seasoning.
- Trim the stems and wash the lettuce heads carefully so they will not break apart. Cut into quarters. Wind several loops of string about each quarter to keep it in shape as much as possible during the cooking.
- Bring the butter, water, and seasonings to the boil in the saucepan. Then add the peas and toss to cover them with the liquid.
- Bury the parsley in their midst. Arrange the lettuce quarters over them and baste with the liquid. Add the onions dispersed among the lettuce quarters.
- In a very heavy, lidded braising pan, bring the peas to the boil and simmer slowly for 20 to 30 minutes or until tender. Several times during this period, toss the peas and lettuce to insure even cooking.
- After 15 minutes remove the lid and check on the liquid. You want it to evaporate into a wet glaze.
- When the peas are tender their cooking liquid should have almost entirely evaporated. Correct seasoning with salt and pepper.
- Discard the parsley and the lettuce strings. Just before serving, toss the peas and onions with the butter.
- Turn them into the vegetable dish, place the lettuce around the edge of the dish, and serve at once.