In a large frying pan over medium heat, cook crumbs in 2 tbsp. oil, stirring, 5 minutes. Stir in zest and 1/8 tsp. each salt and pepper. Cook and stir until golden, 5 more minutes. Pour into a bowl.
In a large pot fitted with a steamer basket, steam beans over 1 in. boiling water, stirring once, 7 to 10 minutes.
Combine 2 tbsp. oil with lemon juice and salt and pepper to taste. Drain beans, toss with dressing, and pour into a shallow bowl. Top with crumbs; serve immediately.
Note: Nutritional analysis is per serving.