In stockpot over medium-high, heat oil. Add onion and sauté until translucent, about 4 minutes. Add garlic, carrot, celery, and sun-dried tomatoes. Continue to cook, stirring often, until carrots have softened, about 5 minutes. Season with salt, coriander, smoked paprika, and cocoa powder. Cook for 1 minute to toast spices before adding white wine. Cook, stirring constantly, until white wine has evaporated, about 2 minutes. Stir in diced tomatoes, water, and pear. Bring soup to a simmer, reduce heat to medium-low, cover, and let soup simmer, stirring occasionally, for 30 minutes. Remove stockpot from heat and stir in unsweetened chocolate until chocolate is fully melted and well incorporated into the soup.