In a bowl, cover the chickpeas with 2 inches of water and stir in the baking soda. Refrigerate for 8 hours or overnight. Drain and rinse.
Preheat the oven to 400°.
In a large saucepan, cover the rinsed chickpeas with 2 inches of water and bring to a boil. Reduce the heat and simmer over medium-low heat until the chickpeas are very tender and starting to fall apart, 30 to 40 minutes or even longer, depending on the freshness of the chickpeas. Drain, reserving 1 cup of the cooking water.
Meanwhile, on a small baking sheet, toss the carrots and the garlic with 2 tablespoons of the olive oil, 1½ teaspoons of the curry powder, and season with salt and pepper. Roast for about 30 minutes, until the carrots and garlic are quite browned and tender.
When the garlic is cool, squeeze the cloves into a food processor. Add the carrots, chickpeas, ½ cup of the cooking liquid, ¼ cup of the olive oil, the remaining 1½ teaspoons curry powder, the tahini, and the lime juice. Process until creamy, adding more cooking liquid if you’d like a looser hummus. Season with salt and pepper.
Transfer to a serving bowl. Using a spoon, make a swirl. Drizzle in some olive oil, garnish with the cilantro and pumpkin seeds, and serve.
Makes about 4 cups
Recipes adapted from Modern Potluck (Clarkson Potter)