In a large skillet, heat 2 tablespoons of the olive oil until shimmering. Add the yellow pepper, shallot and garlic and season with salt and pepper. Cook over moderately low heat, stirring frequently, until just beginning to brown, about 7 minutes. Add the roasted peppers, jalapeño and vinegar. Cover and cook over low heat until the vegetables are very tender, about 10 minutes. Stir in the oregano.