Roast the peppers, along with some thickly-sliced onions and whole peeled garlic cloves. When they're caramelized, place them in a saute pan or small saucepan, with a little liquid of some sort (I abhor using water, vegetable stock is a good choice), and bring it all to a simmer. Cook it down. Puree with a hand blender or transfer to a counter-top blender. Season to taste with salt and pepper. Vinegar is optional.
Personally, I like a little fruit in the sauce, especially if there's a lot of Hab's in there. Grill pineapple is great, as is pineapple juice with the vegetable stock.
Peace, Love, and Vegetable Rights!
Eat Meat and Save the Plants!