This is an easy and rich chocolate mousse recipe that can be made in just one pot with only four ingredients. Simply mix milk, sugar, and agar powder, add chocolate, heat until melted and boiling, then pour into a mold and let it cool and set. It's surprisingly easy, yet the rich chocolate aroma fills your mouth with a luxurious taste. It's perfect for Valentine's Day, but also a great easy-to-make homemade café dessert that chocolate lovers will adore all year round.