Bring 1 quart water to peel in a medium saucepan. Blanch the tomatoes in the water for about 1 minute, just until the skin breaks. Remove the hot tomatoes from the water, drain, and cool for 10 minutes. Pull off and discard the skin. Seed and dice the tomatoes, then set aside.

Melt butte in a large pot over high heat. Add the celery, bell peppers, onions, and tomatoes and sauté 7-10 minutes, until the tomatoes are nearly dissolved and the vegetable begin to caramelize. Reduce heat to medium and add the tomato paste, bay leaf, salt, cayenne pepper, and paprika. Allow the mixture to simmer for an additional 3-4 minutes, until the vegetables are a rich caramel color. Stir in the stock and reduce the mixture at a low rolling boil over medium heat for 30 minutes. Remove and discard bay leaf.