A few slices of tomato, a nice Dijon mustard-based vinaigrette, about 30 minutes of cleaning the purslane over and over in the salad spinner (I can't stress how much dirt these things pick up if you're plucking them from the soil by the root), and cutting the roots off, and presto: a delicious, lemony, salad with crunch-bursty texture.
Whisk olive oil and vinegar until they emulsify. Add salt, pepper, and mustard. Whisk. Adjust seasoning.
Dress the purslane and tomato separately then combine.
Clean the purslane religiously. If you're buying it from the store or the farmers market, lose your religion just a little. Either way, cut off the roots, and with any stems that seem a bit too thick, remove the leaves. Clean and slice your tomato, then keep to the side.