Prepare the vegetables. Preheat your oven to 375F (190C). Prepare 2 baking sheets with foil, parchment, or a silicone baking mat. Carefully slice beets, sweet potatoes, and zucchini into 1/4 inch (.6 cm) strips. In a medium-sized bowl, toss the sliced beets with 1/3 of the olive oil, 1/3 of the herbs, and seasonings (you will be doing this three times). Toss with tongs or hands until beets are completely coated and then lay them on the prepared baking sheet. Repeat this process with the sweet potato and line on the same baking sheet if there is still room, making sure they are not touching. Finally, add the zucchini slices to the bowl with the remaining oil, herbs, and salt, and pepper and toss to combine. Set aside for now.
Bake the beets and sweet potatoes for 20 minutes, then take the pan out and flip so they brown evenly. Add the sliced and seasoned zucchini to the second baking sheet and spread them out evenly so they are not touching. Bake for 10 minutes.
After 10 minutes, check on all the veggies to see if they are fork-tender and slightly darkened. The beets and zucchini may need 5-10 minutes more. Remove the vegetables from the oven when they are fork-tender and slightly darkened. Allow to cool completely before storing in a container.
Assemble the sandwiches. The sandwich will taste best made the same day you eat it. No need to reheat the roasted veggies unless desired. Toast the bread if desired, and top one slice of bread with about 2 tbsps ricotta, and the other slice with about 2 tbsp hummus. On top of the hummus, layer 2-3 slices of beets, sweet potatoes, and zucchini. On the other slice, press the sprouts into the ricotta. Cut the sandwich in half and enjoy!