To make ahead
Cover and refrigerate for up to 5 days.
To cook lentils: Rinse 1 cup dry brown lentils. Place the lentils and 4 cups water in a medium saucepan. Bring to a boil over high heat, stirring occasionally. Reduce heat to medium-low; simmer until tender, 20 to 25 minutes. Drain well and spread evenly on a rimmed baking sheet. Refrigerate until cool, about 25 minutes.