Mash the beans

• Drain and rinse the butter beans, then tip them into a bowl.
• Mash with a potato masher until thick but still slightly chunky.
• Season with salt, black pepper and a drizzle of olive oil.

Fill the sandwiches

• Spread the mashed beans over half of the bread slices.
• Top with the grated cheddar and close with the remaining slices.
• Butter the outside of each sandwich.

Toast the grilled cheese

• Heat a frying pan over medium heat.
• Cook the sandwiches until golden and the cheese melts, turning once.

Warm the tomato soup

• Heat the tomato soup in a saucepan, stirring occasionally.
• Season to taste.

Serve

• Cut the grilled cheese in half.
• Serve hot alongside the tomato soup for dipping.