Preheat the oven to 425°F (220°C).
Wash and dry the sweet potatoes. Prick them all over with a fork, rub with 1 tablespoon of olive oil, and sprinkle with salt.
Bake the sweet potatoes directly on the oven rack for 45-60 minutes, until fork-tender.
While the potatoes are baking, prepare the filling. Heat the remaining olive oil in a large skillet over medium heat.
Add the diced onion and sauté for 3-4 minutes until translucent.
Add minced garlic and cook for another minute until fragrant.
Add the chickpeas, cumin, and paprika. Cook for 2-3 minutes, stirring occasionally.
Mash about half of the chickpeas with the back of a spoon or a potato masher.
Add the chopped spinach, lemon juice, and vegetable broth. Stir and cook until the spinach is wilted, about 2-3 minutes.
Season with salt, pepper, and red pepper flakes if using. Remove from heat.
Once the sweet potatoes are done, remove them from the oven and let cool for a few minutes.
Slice the potatoes lengthwise and gently mash the insides with a fork.
Spoon the chickpea-spinach mixture into each potato.
Drizzle with tahini and garnish with fresh herbs and optional toppings.
Serve immediately and enjoy your nutritious meal!