For the dressing: Combine all the ingredients in a small bowl and season well.
In a bowl, place the spinach, lentils, cucumber, onion, dill and feta. Toss together well. Drizzle over the dressing. Season well and toss once more. Sprinkle over some chopped almonds, if desired.
2 cups baby spinach, 800 g canned lentils, 2 lebanese cucumbers, 1 red onion, 1 cup dill, 80 g feta cheese, almonds