To soft-boil the egg, bring a small saucepan of water to a boil and gently lower in the egg. Simmer for 6 to 8 minutes (depending on whether your egg is smallish or rather large) then remove and place immediately in a small bowl of ice water. Peel underwater and carefully slice into quarters.
Arrange the leaves from your head of lettuce to make a nice nest on your plate. Cut your raw asparagus stalks into one-inch pieces and scatter over the lettuce. Whisk together the balsamic, lemon juice, honey and fresh herbs, then slowly add olive oil, whisking and adding until the dressing reaches your desired thickness. Sprinkle the dressing over the salad, then crumble feta on top and nestle in your egg quarters. Finish with a sprinkling of salt and pepper.