Cook the bacon using your preferred method, until it is nice and crispy. Set aside.
To make the Bloody Mary butter, mix 2 tablespoons of butter in a bowl with the tomato purée, Worcestershire sauce and Tabasco. Pop it in the fridge and chill for 10 minutes.
Meanwhile, spread the remaining butter on one side of each slice of bread and lay them butter side down.
Spread the Bloody Mary butter on the unbuttered sides of the bread, then lay the cheese on 2 of the slices.
Season, top with the bacon and rocket and close the sandwiches with the remaining bread so the butter is on the inside and the plain buttered sides are facing out.
Heat a large heavy-based frying pan on a medium heat and transfer the sandwiches into the pan. Cook for 3 minutes then flip them over and cook for a further 2–3 minutes, or until the cheese has melted and the bread is crispy and golden.