Rinse the fish under the cold tap. Remove the scales and gut if they haven't been removed already. Cut off the head and tail (you can reserve them in the freezer for another recipe like fish soup). Wash it once more inside and out and dry with paper towels.
Cut the fish into steaks (1-inch/ 2.5 cm thick) and place in a bowl. Sprinkle with 2 tablespoons of salt and the lemon juice. Massage the salt and lemon juice into the fish, cover and refrigerate for 30 minutes.
After the carp has marinated, rinse away the excess lemon and salt.
Dry each bell very carefully with a paper towel. Pour the breadcrumbs and the wheat flour into a bowl. Mix the flour with the breadcrumbs. Coat each bell very carefully in this simple breading. Tap off the excess.
Prepare a thick-bottomed frying pan/skillet over medium-high heat and add add the vegetable oil and butter. Heat until the butter has melted and the oil has become hot.
When the oil has heated, it's time to add the fish. Now, work in batches if you need to, placing the fish in the pan and frying it on both sides until it's crispy and golden brown. You should give it around 4-5 minutes per side.
Transfer the cooked carp onto a dish lined with kitchen paper to drain away the excess oil.
Transfer the fish to a serving platter and garnish with whatever you like (lemon wedges, chopped parsley etc) and serve hot.