Preheat the oven to 200 degrees lower / upper heat.
Wash and dry the carrots, mix with oil and salt in an ovenproof dish and cook for about 30 minutes, turning after 15 minutes.
In the meantime, sauté the peeled and very finely chopped or crushed garlic clove in the heated butter and let it simmer for a few minutes on the lowest heat, but do not brown. Fold in the finely chopped parsley, sauté briefly.
Pour the parsley and garlic butter over the cooked carrots, sprinkle with pepper and serve.