Toss the lettuce in the dressing below (using just enough dressing to wet the leaves). Spoon the greens onto a large serving platter then place the other ingredients to your own taste in an attractive manner atop the dressed greens. Rub the tuna with Chinese 5-spice and grill the tuna quickly in a hot grill pan. Slice the tuna (cooked to your liking ---rarer will yield a more tender and flavorful product) and lay over the other salad components and serve.
Vinaigrette for Atkins-friendly Salade Nicoise: ¼ cup red or white wine vinegar 1 teaspoon Dijon mustard ¼ teaspoon salt fresh ground pepper ¾ cup extra-virgin olive oil