Preheat your oven to 425°F (220°C).
Line a baking sheet with aluminum foil and set it aside for easy cleanup.
In a large mixing bowl, combine the 1 lb (16 oz / 454g) prepared green beans, 2 tbsp. (1. 0 oz / 28g) olive oil, and 1 tsp. (0. 1 oz / 3g) minced garlic.
Toss the ingredients until the beans are well coated.
Season the mixture lightly by sprinkling 0. 1 tsp. (0. 02 oz / 0. 5g) sea salt and 0. 1 tsp. (0. 02 oz / 0. 5g) freshly ground black pepper over the bowl, tossing one more time to distribute the spices.
Spread the seasoned green beans in a single, even layer across the prepared baking sheet.
Roast the beans in the preheated oven for about 10 minutes, making sure to stir them once halfway through, until they are tender and lightly browned.
Remove the baking sheet from the oven and immediately serve the beans topped with the 0. 25 cups (1. 0 oz / 28g) freshly grated Parmesan cheese.
Dry the Beans Thoroughly: After washing your green beans, make sure to pat them completely dry with a paper towel before tossing them with olive oil. Any residual water will cause the beans to steam rather than roast, preventing them from getting those delicious caramelized edges.
Keep an Eye on the Garlic: Minced garlic can go from perfectly fragrant to bitter and burnt very quickly in a 425°F (220°C) oven.
Toss the beans thoroughly so the garlic sticks to them rather than resting directly on the hot foil, and pull them out the moment the beans are tender.