Place potatoes in saucepan with enough water to cover. Add 1 tsp. salt. Simmer until tender; 15 - 18 minutes, adding peas in the last 2 minutes; drain. Gently mash with scallions, butter and 1/2 tsp. each of salt and pepper.

Meanwhile, season chicken with 1/2 tsp. salt and 1/4 tsp. pepper. Coat with flour, shaking off excess.

Heat 1 tbsp. oil in large skillet over medium heat and cook half the chicken until golden brown and cooked through, 2 - 3 minutes per side; transfer to plates. Repeat with remaining chicken. Serve with potatoes.