Boil the beetroots in salt water for around half an hour until tender. Check them with a fork to see if they are well cooked. If the fork does not meet serious resistance, the beetroots are done. Drain the water and let the beetroots cool down. Once they are cold enough to handle, peel them and slice the beetroots thinly. Place them into a salad bowl.
Peel and crash the garlic. Mix the garlic with a tea spoon of salt and the red wine vinegar. Let the garlic soak in the vinegar for 5 minutes, than add the olive oil and pepper according to your taste. Mix the vinaigrette well, pour it over the beetroots and blend everything well. Let the beetroots soak up the flavors of the vinaigrette at least for one hour before serving. You can keep this salad in the fridge for about 3 days.