In a small pot, heat the lentils and water on a medium heat. Do not cover. Let the lentils cook until al dente, this will take about 15-20 minutes. Once most of the cooking liquid is gone, you can turn the heat off the lentils and cover the pot, allowing the lentils to continue absorbing water.
In a bowl, combine the remaining ingredients, creating a paste. Pour the kelp and caper mixture into the still warm lentils and mix delicately (as to not break up the lentils). Cover the pot again and let the lentils absorb the flavors and liquid for about 5 minutes.
Pour the lentils into an airtight container to chill for at least an hour before serving.