Take the carpaccio out of the refrigerator fifteen minutes before serving. Ice-cold meat tastes flat because cold locks in the volatile aromas; the full beef flavor only truly develops at room temperature.
Dry-toast the pine nuts in a skillet until golden brown. Keep a close eye on them and shake regularly, as they can burn in thirty seconds. Let them cool on a cold plate.
Whisk the mayonnaise with the truffle tapenade and a splash of lemon juice until it forms a smooth, slightly runny sauce. If it is too thick to drizzle, whisk in a teaspoon of cold water.
Arrange the carpaccio slices in an overlapping pattern on a large cold plate, so the meat doesn't warm up and discolor. Drizzle with a tablespoon of olive oil and the balsamic vinegar, and grind some black pepper over it.
Loosely scatter the arugula over the center and tuck the sliced sun-dried tomatoes in between. Spoon dollops of the truffle mayonnaise over it, shave the Parmesan into wide flakes over the top using a vegetable peeler, and scatter the pine nuts over everything. Finish with the remaining olive oil. Lean beef and Parmesan together provide plenty of protein, the mayonnaise and pine nuts supply the fat, and there are virtually no carbohydrates involved.