Line a baking sheet with foil or parchment paper, and place the pepper on it. Slide under the broiler, and broil until the skins are lightly charred, and peppers soft. Turn as needed to char all surfaces. Place in a container for 10 minutes, peel, seed, and coarsely chop.
Heat the olive oil in a heavy bottom pot - I use my Creuset. Add the onion and scallions until softened and starting to brown, about 10 minutes. Add the cauliflower, garlic, salt, and red pepper flakes. Sauté for another 10 minutes.
Pour in the vegetable broth, Parmesan rind, and stewed tomatoes. Simmer for 20 minutes to concentrate the flavors.
Add the chickpeas, roasted peppers, oregano, and pesto, and continue to simmer until the chickpeas are warmed through, about 5 minutes. Stir in the Swiss chard and simmer until completely wilted. Stir in the balsamic vinegar.
Serve piping hot with Parmesan cheese and additional pesto.