Preheat oven to 375 degrees F and line a baking sheet with parchment paper.
In a large bowl, toss the chopped carrots with half of the olive oil. Spread the carrots over the baking sheet and roast for 40 minutes, tossing halfway through cooking.
In a large pot, heat the remainder of the olive oil. Add the onion and celery and cook for 7-10 minutes or until softened. Add garlic and cook 2 to 3 minutes longer.
Add the roasted carrots, vegetable broth, white beans, turmeric and tahini to the pot. Use an immersion blender to puree until completely smooth. Add lemon juice, salt, and pepper to taste.
Keep warm on the stove and if serving as an appetizer, divide between demitasse cups and garnish with raw pumpkin seeds.