Char the red bell pepper over a flame until it’s blackened all around. Place it in a bowl and cover with plastic wrap. Set aside to cool for 30 minutes.
Heat oven to 350°. Put tomatoes and garlic in a pan with 2 tablespoon extra-virgin olive oil, salt and pepper; toss, and place in oven for an hour (occasionally toss the tomatoes).
Once red pepper has cooled, remove plastic wrap and peel off the charred skin.
Put bell pepper, tomatoes and garlic, and their oil in a food processor with nuts, sherry vinegar, sweet, smoked paprika, cayenne, and lemon juice. Start up the processor and slowly pour in remaining oil. Salt and pepper to taste.