Preheat oven to 350 degrees. On a rimmed baking sheet, spread the almonds and cook in preheated oven until lightly colored about 8 minutes. Cool and move to a small bowl and set aside. Increase oven temperature to 425 degrees.
In a medium saucepan, add lentils and 2 cups of water. Bring to a boil, reduce heat and simmer lentils, adding more water if necessary, until lentils are tender about 20 minutes. Drain lentils thoroughly, add 1/2 teaspoon of salt and mix thoroughly, then cool to room temperature. Set aside.
In a small bowl, make the spice mix by combining cumin, cinnamon, ginger, black pepper, and 3/4 teaspoon salt. On a rimmed baking sheet (used the same one you toasted almonds on), toss cauliflower with 1/4 cup olive oil and until evenly coated. Evenly sprinkle spice mix over cauliflower. When oven has reached 425 degrees, roast cauliflower 20- 25 minutes or until it's browned nicely on the bottom. Allow to cool and set aside.
In a bowl, large enough to later accommodate all salad ingredients, make the dressing by whisking the tahini, lemon juice, honey, 1 Tablespoon olive oil and 2 Tablespoons water together until smooth. Add the room temperature almonds, cauliflower, lentils, then dates, red onion, and arugula or spinach and toss until evenly coated with dressing. Taste for seasoning and add salt and pepper as needed.