Peel the garlic and press it through a garlic press. Wash the marjoram, shake dry, pluck the leaves from the stalks and chop finely. Mix butter, garlic, lemon juice and marjoram.
Season to taste with salt and pepper. Clean the beetroot tubers, peel them (preferably wearing rubber gloves) and cut them into approx. 1 cm thick slices. Spread slices thinly with butter and put them back together to form balls.
Wrap the balls individually in foil and close tightly. Cook in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 45 minutes. In the meantime, mix cheese, crème fraîche and milk with a fork.
Peel onions and cut them into rings. Season with salt, let it stand for a short time and dust with flour. Heat oil and fry onion rings in portions until crispy brown. Take them out and let them drip off on kitchen paper.
Arrange the finished beetroot with dip and onion rings on plates. Season with freshly ground pepper.