Wash broccoli, divide into small pieces and cook in salted water until al dente. Rinse with cold water and drain well.
Chop onion and garlic finely. Heat some oil in a pan and sauté garlic and onion. Add half of the broccoli, fry briefly and pour in cream. Bring to a boil and then puree with a hand blender. Season with salt and pepper and fold in the remaining broccoli.
For the potato cakes peel potatoes, onion and garlic and grate finely. Stir in egg and sour cream, season with salt and pepper. Heat oil in a nonstick frying pan, place heaped tablespoons of the mixture into the pan to shallow-fry. Lower the heat to medium, flatten each latke with the back of a spoon and fry for about five minutes on each side, turning over when the edges turn golden-brown. If the heat is too high, the latkes will become dark-brown on the outside before they are cooked inside.
Fill potato pancakes in the middle with broccoli cream and beat up like an omelet.