Preheat the oven to 190 °C/375 °F and position a rack in the middle of the oven. Rub a rimmed baking sheet with a thin glaze of oil.
Arrange the tomatoes, skin side down, on baking shee. Coat the bell pepper and onions with oil and arange them on the baking sheet along with the garlic. Place the peppers skin side down as well. Season with salt and pepeer, then bake until the tomatoes start to collapse and the onions start to brown and caramelize, about 45 minutes. Turn the onions if they start getting too dark on the bottom.
Peel the garlic, remove the skin from the peppers and dump all of the roasted vegetables into a big bowl, and puree with a hand held blender *. Blend in the stock and smoked paprika and adjust the seasoning to taste.
For a nicer texture pass through a sieve and serve with bread.