Follow these steps carefully to create perfectly textured and flavourful Cold Lentil Salad Cups:

1. Cook the Lentils: Thoroughly rinse the dry lentils under cold running water using a fine-mesh sieve. This removes any dust or debris. Combine the rinsed lentils and 3 cups of water or vegetable broth in a medium saucepan. Bring the mixture to a boil over medium-high heat. Once boiling, reduce the heat to low, cover the saucepan, and let the lentils simmer gently. Cook for 20-30 minutes, or until the lentils are tender but still hold their shape (al dente). Avoid overcooking, as mushy lentils will detract from the salad’s texture. Check them frequently towards the end of the cooking time.
2. Drain and Cool Lentils: Once cooked, immediately drain the lentils thoroughly in the fine-mesh sieve. Rinse them briefly under cold water to stop the cooking process and help them cool down faster. Spread the drained lentils on a baking sheet or a large plate in a single layer to cool completely to room temperature. This step is crucial; adding warm lentils to the vegetables can make them wilt and affect the overall texture. Allow at least 15-20 minutes for cooling.
3. Prepare the Vegetables and Herbs: While the lentils are cooking and cooling, prepare the rest of the salad components. Finely dice the red bell pepper and the seeded cucumber. Finely mince the red onion. Chop the fresh parsley and fresh mint. Having everything prepped and ready will make assembly quick and easy. Aim for a consistent, small dice size for the vegetables for the best eating experience.
4. Make the Dressing: In a small bowl or a jar with a tight-fitting lid, combine the extra virgin olive oil, freshly squeezed lemon juice, Dijon mustard, minced or grated garlic, salt, and freshly ground black pepper. Whisk vigorously (or shake the jar) until the ingredients are well combined and the dressing is emulsified (slightly thickened and uniform). Taste the dressing and adjust seasoning if necessary – you might prefer more salt, pepper, or lemon juice.
5. Combine the Salad: In a large mixing bowl, combine the completely cooled lentils, diced red bell pepper, diced cucumber, minced red onion, chopped parsley, and chopped mint. Ensure the lentils are no longer warm to the touch before adding them.
6. Dress the Salad: Pour the prepared dressing over the lentil and vegetable mixture in the large bowl. Use a spatula or large spoon to gently toss everything together until the ingredients are evenly coated with the dressing. Be careful not to mash the lentils.
7. Chill the Salad: Cover the bowl tightly with plastic wrap or transfer the salad to an airtight container. Refrigerate for at least 30 minutes before serving. This chilling time allows the flavours to meld and deepen, resulting in a much tastier salad. The salad can be made several hours or even a day in advance (see tips).
8. Prepare Lettuce Cups: Just before serving, carefully separate the leaves from the head of lettuce. Choose the most cup-shaped, intact leaves. Wash them gently under cold running water and pat them completely dry with paper towels or use a salad spinner. Wet lettuce leaves will make the cups soggy and dilute the flavour.
9. Assemble and Serve: Spoon a generous amount of the chilled lentil salad mixture into each prepared lettuce cup. Arrange the filled cups on a platter or individual plates. Serve immediately for the best texture and freshness.