For the dressing: Stir the maple syrup into the almond butter. Add the vinegar, salt, and pepper and stir to fully blend. The dressing may be prepared in advance and stored in a jar or covered container in the refrigerator for several days. Stir or shake well before using.
Preheat the oven to 400 degrees F. Chop the beets and sweet potatoes into bite-size pieces.*** Place on a lightly-greased baking sheet, toss with the olive oil, and roast for 20-30 minutes, tossing once halfway through, or until the veggies are just tender. Remove from the oven and let cool.
Meanwhile, prepare the lentils according to the package directions (this will vary based on variety of lentil chosen), drain, and set aside. The lentils may be prepared up to several days in advance and refrigerated. Tip: When cooking the lentils, add 2 teaspoons of salt to 4 cups of cooking water. Most of the salt will be drained off, but this will result in more flavorful lentils.
When ready to assemble the salad, place the kale in a large salad bowl, and sprinkle with the 3/4 teaspoon of kosher salt. Massage the kale with your fingers for about 2 minutes. The leaves will soften and become a darker shade of green. Add the beets, sweet potatoes, and lentils. Drizzle with approximately 2/3 of the dressing, and toss well. Add more dressing to taste, or reserve for later use. Sprinkle with the sunflower seeds just before serving. If you anticipate leftovers, you may wish to sprinkle the seeds over individual servings for best crunch.