Prepare and wash all your vegetables. Trim the radishes and slice them lengthwise, making all the pieces more or less the same size. Also wash and dry the greens, and ready the leeks, peas, and asparagus. (If you wish, you can make a stock to use in this dish with the leek trimmings, pea pods, asparagus peels, some tarragon, and salt. You'll need only 1 cup or so.)
When you are about ready to eat, melt a few teaspoons butter in a heavy skillet over medium heat. Add the leeks and 1/2 cup of the water and simmer for 5 minutes. Season with a few pinches of salt, add the radishes and asparagus, and simmer for 3 minutes. Next, add the peas and radish greens, making sure there is liquid in the pan as you go and adding more if needed. Continue cooking until the peas are bright green and the leaves are tender, about 2 minutes longer. The radish leaves will wilt and look a little funky, but they will taste mild and slightly nutty.
When the vegetables are done, remove from the heat, add a heaping spoonful of butter, season with salt, and stir in the tarragon and lemon juice. Taste and adjust the seasonings, then serve and enjoy your garden in a bowl.
Reprinted with permission from Vegetable Literacy by Deborah Madison, copyright © 2013. Published by Ten Speed Press, a division of Random House, Inc.