1. For the potato rosti, grate the potatoes coarsely into the corner of a clean tea towel. Fold the towel over the potato to form a ball and squeeze to remove as much water as possible.
2. Melt the butter (or clarified butter) and mix it with the oil. Heat 4 blini pans and pour a little of the butter and oil into each pan.
3. Open the cloth and season the potato. Divide the potato mixture between the pans and fry to a golden brown on a medium heat. If the pan appears dry, add a little oil around the potato.
4. When the first side is golden brown, turn each rosti over, adding a little more oil as required and finish cooking. Transfer the cooked rosti to a baking tray for later reheating.
5. For the toppings, lay the bacon slices onto a tray lined with baking paper and bake in a 200C oven for about 12 minutes until crisp and golden. Take the rosti potatoes (reheated briefly in a hot oven if necessary) and arrange the tomatoes, bacon and cheese on top of each, layering the ingredients as you go.
6. Place the whole thing in the oven to warm through and for the cheese to slightly melt. Take care not to let the cheese melt too much.
7. When hot, serve the feasts on warm plates with a little of the tomato oil around and top with rocket leaves.