Heat butter in a pan, add milk and mix well.
Add milk and give a quick stir.
Your cheese dip is ready.
Mix mayonnaise with onion and capsicum. Add salt, black pepper as per taste
Take bread slice. Apply chutney to one side. Spread the mayonnaise filling, cover with another chutney spreaded bread
Apply butter to both the side of sandwich and grill them.
Serve hot with cheese dip.