Chard works well with spinach in this fall salad, but be sure to remove tough stems and use only the leaves. The vinaigrette is also good on grilled or roasted vegetables. Tahini is available in many supermarkets, or try Middle Eastern markets for more choices.
In a medium bowl, whisk together the tahini, olive oil, vinegar, lemon juice, honey, salt and pepper until combined. Stir in the garlic clove. Let sit while you prepare the salad.
In a large bowl, toss together the spinach and chard. Separate the onion and arrange the slices on top, then sprinkle on the dried cranberries.
Strain the garlic clove from the dressing, then drizzle it on the salad. You may not need all of it; use your discretion. Toss and serve immediately.