How to Make It
Preheat oven to 450°F. Toss together carrots, 1 1/2 teaspoons oil, and 1/2 teaspoon salt on a large foil-lined baking sheet. Roast at 450°F until carrots are fork-tender, about 20 minutes, stirring once.
Meanwhile, heat remaining 1 1/2 teaspoons oil in a Dutch oven over medium. Add onion; cook, stirring often, until lightly browned, 10 to 15 minutes.
Add curry paste, grated ginger, and crushed red pepper to Dutch oven, and cook, stirring constantly, until fragrant, 1 minute. Add cooked carrots, cannellini beans, vegetable stock, coconut milk, and remaining 1/8 teaspoon salt. Bring to a boil over high. Reduce heat to medium, and simmer 5 minutes.
Pour mixture into a blender. Remove center of blender lid to allow steam to escape; secure lid on blender. Place a clean kitchen towel over opening in blender lid. Process until smooth, about 1 minute.
Stir in lime juice and black pepper. Divide soup among 6 bowls; top evenly with cilantro, avocado, and lentils.