Preheat the oven broiler to high. Place the oven rack in its second highest position.
Place the whole red and yellow peppers on their sides on a baking sheet and broil for 5 minutes on each side, leave about 3 inches between the flame and the top of the peppers. This will take about 20 minutes or so. The skins will be charred and he flesh of the peppers soft.
Place the peppers in a glass bowl and cover tightly with plastic wrap. Let cool to room temperature for 20 minutes.
Slice the cooled peppers lengthwise in half and remove and discard the skins, seeds, and ribs. Slice into 1/4 inch wide strips and set aside.
Heat the olive oil in a large saucepan over medium heat and sweat the onions for 5 minutes, or until just soft and translucent. Add the garlic and saute for 2 minutes.
Stir in the chile flakes and paprika, then add the roasted peppers strips, peppadews, bay leaf, rosemary, and thyme. Lower heat and cook at a low simmer for 20 minutes to allow flavors to meld.
Stir in the red wine vinegar and capers and simmer for 5 minutes. Remove and discard the bay leaf, rosemary, and thyme. Stir in the salt.
Transfer to a serving bowl and serve at room temperature.