Place bell peppers on large baking sheet. Roast in the oven for 30 - 40 minutes, or until the skins begin to blister, turning halfway through. Transfer bell peppers to large food safe plastic bag. Tie bag, then let stand for 15 minutes, or until bell peppers are cool enough to handle. Peel off blistered skin, remove tops, ribs and seeds, then coarsely chop bell peppers and set aside.
With a sharp knife score an X in the bottom of each tomato. Place in saucepan of boiling water for 30 seconds, then transfer tomatoes with slotted spoon to a bowl of ice water. Peel off skin then coarsely chop tomatoes.
Place bell peppers, tomatoes and seasonings in large pan over a medium-low heat. Cook for 35-45 minutes, or until vegetables are very soft, stirring frequently. Stir in sugar and tomato purée. Cook for 15 minutes, or until thickened, stirring frequently. Stir in lemon juice.
Serve warm, or at room temperature with pita or naan bread or crackers. Alternatively refrigerate and serve cold.