Step 1

Place potatoes in a steamer basket in a large saucepan. Add water to saucepan to just below the basket. Bring to boiling. Steam, covered, 12 minutes or until tender. Transfer potatoes to a large bowl; let cool. Return steamer basket to saucepan. Place green beans in steamer basket. Steam, covered, 5 to 8 minutes or until crisp tender. Remove steamer basket from pan and let beans cool. Season beans and potatoes with salt and pepper. Set artichoke hearts in a colander set in the sink and pour hot water over them; drain well.

Step 2

For Tahini Sauce, stir together tahini, lemon juice, garlic, cumin, cayenne pepper (if using). Season to taste with salt and pepper. Stir in ¼ cup water, 1 tablespoon at a time, to reach drizzling consistency.

Step 3

Place lettuce in bowls. Arrange potatoes, beans, artichoke hearts, chickpeas, tomatoes, and onion in bowls. Sprinkle with olives and thyme leaves. Drizzle with Tahini Sauce.