Remove the seeds and membrane from the red bell pepper. Cut it in half along the lobe lines to help it lay flat.
Place a cooling rack over a gas burner, and turn the burner on high heat. (Alternatively, preheat a broiler to high heat, position an oven rack close underneath, and line a sheet tray with aluminum foil.) Make an aluminum foil pouch just large enough to hold the pepper.
Roast the pepper and tomatoes: Place the pepper, skin-side-down, on the rack over the flame and then place the tomatoes on the rack over the flame. Use tongs to move the peppers and turn the tomatoes until their skins are evenly blackened and the tomatoes are soft. (Alternatively, place the vegetables on the sheet tray under the broiler, and turn the tomatoes as necessary.) Transfer the pepper to the foil pouch and allow it to steam in its own heat for about 5 minutes, until cool enough to handle. Cool the tomatoes enough to handle them.
Cut the cores out of the tomatoes, scrape off the charred skins, and coarse-chop them.
Scrape the charred skins off the pepper and cut it into rough dice.
Chop the step 2 garlic and place it in a blender along with the roasted pepper, tomato, tomato purée, bread crumbs, and some salt
Combine the olive oil and almonds in a small sauté pan and place over low heat. Cook, stirring constantly, until the almonds just begin to brown. Turn off the heat, add the crushed red pepper and paprika, and cook a second or two longer until fragrant. Take care not to let the almonds or spices get too brown.
Immediately pour the almond mixture into the blender, using a plastic spatula to scrape in all of the oil.
Turn on the blender to low speed and purée just until combined.
Stir in the vinegar.
Taste and evaluate for salt and acidity.
Transfer the Romesco sauce into a container.