Roast peppers (skin-side up) under broiler or on a sheet at 450°F until charred. Flip to char all sides, then transfer to a bowl and cover to steam 10 minutes; peel off skins.
Sauté onion in olive oil until soft, add garlic and smoked paprika, cook 1 minute.
Add tomatoes (or canned), peeled peppers, and broth. Simmer 15 minutes to meld flavors.
Blend soup until smooth using an immersion blender or in batches in a blender. Stir in cream or yogurt if using, then season to taste.
Reheat gently, garnish, and serve with crusty bread.