Heat the oil in a large non-stick frying pan over medium-high heat. Add half the chicken and cook for 4-5 minutes each side or until cooked through. Transfer to a plate and set aside for 5 minutes to rest. Repeat with the remaining chicken.

Meanwhile, combine the silver beet, cabbage and mung beans in a large bowl. Use a fork to whisk together the sour cream, mustard and lemon juice in a small bowl until well combined.

Thinly slice the chicken across the grain. Divide the silver beet salad among serving plates and top with chicken. Drizzle with sour cream dressing and season with pepper. Serve immediately.