• Strip the chard leaves from the stems; thinly slice the leaves and coarsely chop the stems, keeping them separate. Set aside the chard stems for the stir-fry.

In a medium bowl, combine the chard leaves and quick-pickle brine. Season with salt and pepper and gently massage the leaves. Let stand, stirring occasionally, while you prepare the rest of the meal.

• Peel and thinly slice enough onion to measure 1 cup [2 cups].
• Trim the root ends from the scallions; thinly slice the scallions on the diagonal, keeping the white and green parts separate. Set aside the green parts for garnish.
• Rinse the white beans.
• Thinly slice the mushrooms.
• Coarsely chop the kimchi, reserving any kimchi liquid.

In a medium sauce pot, combine the tofu and enough water to cover. Bring to a boil and cook until heated through and tender, 3 to 5 minutes. Using a slotted spoon, transfer to a cutting board to cool slightly. Cut the tofu into ½-inch cubes.
While the tofu boils and cools, prepare the stir-fry.

In a wok or large frying pan over medium-high heat, warm 1 to 2 tablespoons oil until hot but not smoking. Add the chard stems, onion, and white parts of the scallions, season with salt and pepper, and cook, stirring occasionally, until starting to soften, 3 to 5 minutes.
Stir in as much gochujang as you like and cook until fragrant, about 30 seconds. Stir in the beans and mushrooms and cook until the beans are warmed through and the mushrooms are just starting to soften, 1 to 2 minutes. Stir in the stir-fry blend, kimchi, and any kimchi liquid and cook until fragrant and warmed through, 1 to 2 minutes. Remove from the heat and season to taste with salt and pepper.

Arrange the tofu in individual bowls. Serve the kimchi stir-fry and pickled chard on top or alongside. Garnish with the green parts of the scallions and serve.