Preparation Cook onion with bay leaf and 1/2 teaspoon salt in oil in a 4- to 5-quart heavy pot over medium-high heat, stirring occasionally, until softened, about 5 minutes. Add carrot and celery and cook, stirring, until softened, about 3 minutes. Stir in tomato paste and cook, stirring, 1 minute, then add sweet potato, Yukon Golds, broth, water, and 1/4 teaspoon pepper. Simmer, covered, until vegetables are tender, about 20 minutes. Discard bay leaf. Purée 1 cup soup in a blender (use caution when blending hot liquids) and return to pot. Bring to a simmer, then stir in peas and dill and cook until peas are heated through, about 3 minutes. Season with salt and pepper.
Preparation Cook onion with bay leaf and 1/2 teaspoon salt in oil in a 4- to 5-quart heavy pot over medium-high heat, stirring occasionally, until softened, about 5 minutes. Add carrot and celery and cook, stirring, until softened, about 3 minutes. Stir in tomato paste and cook, stirring, 1 minute, then add sweet potato, Yukon Golds, broth, water, and 1/4 teaspoon pepper. Simmer, covered, until vegetables are tender, about 20 minutes. Discard bay leaf. Purée 1 cup soup in a blender (use caution when blending hot liquids) and return to pot. Bring to a simmer, then stir in peas and dill and cook until peas are heated through, about 3 minutes. Season with salt and pepper.