Add the green beans, olive oil, paprika, cumin, black pepper, garlic, parmesan cheese, thyme and rosemary leaves if using and salt to taste into baking pan, toss with a wooden spoon until the green beans are well and evenly coated.
Bake the green beans for about half an hour.
Stir the green beans once to make sure all sides are evenly roasted.
Return the baking pan into the oven and continue to bake for another 15 minutes, or until the green beans become tender-crisp and start to become brown at some spots.