Cook lentils: Add lentils, 3 cups of water and a pinch of salt into a medium saucepan. Bring to a boil, reduce heat, partially cover and simmer until lentils are soft, about 25 minutes. Drain through a fine strainer and rinse quickly with cold water to cool. Drain again, set lentils aside and allow to cool. This step can be done ahead of time. Just cook your lentils, cool and store them in the fridge until you’re ready to make the salad.
Combine ingredients: In a large bowl, add the cooled lentils, tuna, red onion, bell pepper, cucumber, raisins and cilantro into a large bowl and toss to combine.
Make dressing: In a small bowl or measuring cup, mix together apple cider vinegar, maple syrup, mustard, turmeric salt, pepper, cayenne, cinnamon and nutmeg. Whisk in olive oil and toss over the lentil tuna mixture.
Serve: Refrigerate until ready to eat. Add the chopped avocado just before serving. Serve with crackers for a snack or appetizer, on bread or a wrap for a sandwich or over a bed of greens. Salad should last 3-4 days in the fridge.