Slice any larger potatoes in half; place in Multipurpose Steamer. Cover; microwave on high 4 min. Remove from microwave and stir or toss potatoes. Add Multipurpose Steamer Tray; top with beans. Cover; microwave 4 min. Potatoes should be tender and beans tender-crisp.
Drain tuna; place in a bowl. Season with dressing mix and gently break apart into large chunks while mixing.
Slice cucumber.
To serve, divide warm potatoes, greens beans, tuna, and cucumber between four bowls. Top with olives and eggs, if using, and drizzle with dressing. Serve immediately.