Wash the potatoes, dab dry and cut in half. Brush the baking tray with oil and sprinkle with salt. Place the potatoes on the baking tray with the cut side down and bake in the preheated oven (electric range: 200 °C/ gas: level 3) for about 20 minutes.
Clean, wash, quarter and seed the tomatoes. Dice the flesh. Peel and finely chop the onion. Wash the thyme and remove the leaves. Mix tomatoes, onion, thyme, cream cheese and egg yolk. Clean and wash spring onions and cut into fine rings.
Halve the bacon and cut the cheese into thin slices. Spread fresh cheese mixture on half of the potatoes. Cover remaining potatoes with spring onions, cheese and bacon. Bake potatoes at the same temperature for another 10 minutes.