1. Preheat the broiler. Rub the tomato and jalapeño with 2 teaspoons of the oil and place them on skin side up on a baking sheet.. Place the vegetables in the broiler and cook, turning with tongs occasionally, until they are lightly charred all over. Remove from the oven, cover with a towel and set aside until cool enough to handle.

2. Core and coarsely chop the tomato, collecting the juices in a bowl. Scrape off the stem and charred jalapeño skin with the tip of a paring knife. Coarsely chop the jalapeño, discarding the seeds to reduce the heat, if desired. In the bowl of a food processor fitted with a metal blade, puree the tomato, its juice and the jalapeño.

3. In a large, heavy skillet, heat the remaining ½ cup of oil over medium-high heat. Add the onion and cook until soft, about 8 minutes. Stir in the garlic and chorizo and cook until the chorizo renders its fat, about 5 minutes. Stir in the black-eyed peas and tomato mixture. Cook until the peas start to break down, about 30 minutes, then mash some or all of the peas with the back of a spoon. Season to taste with salt and serve warm.