How to Make It
In a steamer basket set over 1 inch of boiling water, steam the potatoes until tender, about 15 minutes. Meanwhile, in a small bowl, combine the olive oil, truffle oil, lemon juice, lemon zest, salt and pepper.
In a bowl, toss the mâche with 1 tablespoon of the dressing; arrange on a platter. Add the potatoes to the bowl and toss with the remaining dressing. Mound the potatoes on the mâche and sprinkle with the mint.