In a small saucepan, bring 1 cup of water to a boil. Add lentils, cover, and reduce heat to a simmer. Simmer for 30 minutes until all the water has absorbed.
Preheat the oven to 425F. Break the cauliflower into bite-sized florets and place them in a large bowl. Add olive oil, salt, and curry powder and toss until the florets are evenly coated. Spread evenly onto a baking sheet and bake for 25 minutes, flipping once.
Place the kale in a large bowl. Add olive oil and salt and gently massage for 1-2 minutes until the kale is richer green, tender, and shiny. Set aside while preparing the remaining salad ingredients.
Combine all the ingredients for the tahini dressing in a small blender and blend until smooth.
When lentils and cauliflower are done, combine them with the kale in a large salad bowl. Add avocado and red onions. Toss with lemon tahini dressing and serve immediately.