Pat beef cubes dry and season lightly with 1/2 tsp salt and 1/2 tsp pepper. Heat a large Dutch oven or heavy-bottomed pot over medium-high heat. Add the vegetable oil. In batches (don’t overcrowd), sear beef cubes until deeply browned on all sides, 3–4 minutes per batch. Transfer seared beef to a plate.

Sauté aromatics

Reduce heat to medium. Add a touch more oil if needed and sauté the diced onion until translucent, 4–5 minutes. Add minced garlic and grated ginger; cook until fragrant, about 1 minute.

Build braising liquid

Stir in gochujang, soy sauce (or tamari), brown sugar and rice vinegar, scraping up browned bits from the pot. Add beef stock and 1 cup water and bring to a simmer.

Braise

Return seared beef to the pot, nestling pieces into the liquid. Bring to a gentle simmer, then cover and transfer to a 325°F (160°C) oven, or keep on the stovetop at a low simmer. Braise until beef is tender and shreds easily, 2 to 2½ hours.

Finish

When beef is tender, remove from oven. Skim off excess fat if desired. Stir in toasted sesame oil and adjust seasoning with remaining salt and pepper. Using two forks, shred beef into bite-sized strands. If sauce is thin, reduce on stovetop over medium-high heat until slightly thickened, 5–8 minutes.

Kimchi & Quick Pickles

While beef braises, prepare quick pickles. In a small bowl combine rice vinegar, 3 tbsp water, 1 tsp sugar and 1 tsp salt; stir until dissolved. Toss julienned daikon and carrot in the pickling liquid and let sit at room temperature for at least 20 minutes (or refrigerate up to 2 hours). Drain before using.

Drain kimchi well to remove excess liquid. If kimchi pieces are large, roughly chop to bite-sized pieces. Keep chilled until assembly.

Chili Crema & Garnishes

In a bowl, whisk together sour cream (or yogurt), gochugaru (or cayenne), lime juice and 1 tsp salt until smooth. Taste and adjust heat or acidity. Transfer to a squeeze bottle or bowl for easy drizzling.

Roughly chop cilantro and thinly slice scallions. Prepare lime wedges and thin radish slices for garnish.

Taco Assembly

Warm corn tortillas in a dry skillet over medium heat about 20–30 seconds per side, or wrap in damp paper towel and microwave 30–45 seconds until pliable.

Build tacos: place a spoonful (about 2–3 tbsp) of shredded Korean braised beef in center of each warm tortilla. Top with a small amount of drained kimchi (about 1–2 tbsp), a few pickled daikon/carrot strips, a couple thin radish slices, and a sprinkle of sliced scallion.

Drizzle chili crema over the toppings, add a few cilantro leaves, and finish with a squeeze of lime. Serve immediately.