In a large skillet, heat oil over medium-high heat until hot. Add green beans, salt, and pepper. Sauté in batches until beans are just tender, 5 to 7 minutes. Return all beans to skillet; toss with garlic powder and onion powder. Remove from heat.

In a medium skillet, melt butter over medium heat. Add garlic; cook, stirring constantly, until fragrant, about 2 minutes. Add pine nuts; cook, swirling pan occasionally, until nuts are golden brown, about 3 minutes. Pour nut mixture over sautéed beans; add lemon zest and oregano, tossing well to coat.