Preheat oven to 425 degrees F. Line 2 baking sheets with foil or silicone baking mats. Drizzle each with about 1 TBSP olive oil.
Spread the sweet potatoes and/or squash on one baking sheet, and spread the beets and Brussels sprouts on the second baking sheet. Season with salt, if desired, and toss to coat in the oil.
Roast the veggies for 40 or so minutes, or until tender and cooked through. Remove from oven.
While veggies are roasting, prepare the dressing: whisk together the tahini, maple syrup, vinegar, lemon juice, and garlic. Add cold water 1 TBSP at a time and mix until dressing is thinned out and pourable. This step can also be done in advance, and the dressing can be kept in the refrigerator. Simply remove from the fridge and bring to room temperature about one hour before starting.
Finely slice the kale into small pieces (or if using spinach, tear into pieces), and lightly massage in olive oil and sea salt to soften. Or, you can also add it to a medium skillet and sauté it lightly until softened.
Combine the kale (or spinach) with the remaining salad ingredients and toss well. Pour about half of the dressing over top (add more water if it has thickened), mix well, and then pour the remaining dressing on top. Mix everything up one last time, and then serve.