• Rinse the quinoa.

In a small sauce pot, combine the quinoa and 1 cup [2 cups] lightly salted water. Bring to a boil, reduce to a simmer, cover, and cook until the quinoa is tender and the water is absorbed, 15 to 20 minutes.
While the quinoa cooks, prepare the cabbage slaw.

In a medium bowl, combine the cabbage and quick-pickle brine. Season with salt and toss to coat. Let stand, stirring occasionally, while you prepare the rest of the meal.

• Peel and thinly slice the shallots.
• Scrape off any seeds from the roasted red peppers; coarsely chop the peppers.
• Rinse the black beans.

In a large frying pan over medium heat, warm 1 to 2 tablespoons oil until hot but not smoking. Add the shallots, season with salt, and cook, stirring occasionally, until softened and lightly browned, 3 to 5 minutes. Stir in the taco seasoning and cook until fragrant, about 1 minute. Add the red peppers, beans, and ¼ cup [½ cup] water and bring to a simmer. Cook, stirring occasionally, until the peppers and beans are heated through, 2 to 3 minutes. Stir in the cooked quinoa. Remove from the heat and season to taste with salt and pepper.
While the filling cooks, prepare the garnishes and the tortillas.

• Coarsely chop the cilantro.
• Cut the lime into wedges. [Cut 1 lime into wedges; save the remaining lime for another use.]
• Remove 6 [12] tortillas from the package; save the rest for another use.

On the stovetop directly over a flame, or in a dry large frying pan over medium heat, warm the 6 [12] tortillas until just pliable and warmed through, about 30 seconds per side. Transfer to a clean kitchen towel, cover, and keep warm.

Transfer the tortillas to individual plates and fill with the quinoa–black bean mixture. Garnish with the cabbage slaw and cilantro. Crumble the queso fresco over the top and serve with the lime wedges.