Preheat your oven to 400°F (200°C).
In a large mixing bowl, combine the halved baby potatoes, olive oil, minced garlic, dried thyme, salt, and black pepper. Toss until the potatoes are well coated.
Spread the potato mixture in a single layer on a baking sheet. Roast in the preheated oven for 20 minutes.
While the potatoes are roasting, prepare the green beans by blanching them in boiling water for 3-4 minutes until bright green and tender-crisp. Drain and immediately transfer them to a bowl of ice water to stop the cooking process.
After 20 minutes, remove the potatoes from the oven and add the blanched green beans to the baking sheet. Drizzle with lemon juice and toss everything together.
Return the baking sheet to the oven and roast for an additional 10-15 minutes, or until the potatoes are golden and tender.
Remove from the oven and garnish with fresh parsley before serving.