Freeze pork tenderloin until firm around the edges, 30–45 minutes. While pork is freezing start rice.

Combine chili paste, brown sugar, ginger, garlic, 2 Tbsp. soy sauce, and 2 tsp. sesame oil in a resealable plastic bag (or medium bowl if you aren’t feeling the plastic). Thinly slice pork with a long sharp knife. Add to marinade, seal bag, and knead to thoroughly coat. Let sit at least 10 minutes and up to 2 hours.

Heat 1 Tbsp. vegetable oil in a large nonstick skillet over medium-high. When oil is very hot, add half of pork in a single layer; season very lightly with salt. Cook, undisturbed, increasing heat to high if needed, until dark brown underneath, about 1 minute. Toss pork, breaking up with tongs or a wooden spoon, and continue to cook, tossing, until cooked through, about 1 minute more. Transfer to a plate. Repeat with another 1 Tbsp. vegetable oil and remaining pork (you may want to briefly remove skillet from heat when adding more oil so it doesn’t spatter). Wipe out skillet.

Heat remaining 1 Tbsp. vegetable oil in skillet over medium-high. Add carrots and cook in a single layer, undisturbed, until beginning to soften and brown underneath, about 2 minutes. Add collard greens and toss to wilt. Cook, tossing occasionally, until vegetables are crisp-tender, about 2 minutes.

Combine vinegar and remaining 1 Tbsp. soy sauce and ¼ tsp. sesame oil in a small bowl.

To serve, divide rice among bowls and arrange pork and vegetables over. Top each with some scallions and a spoonful of gochujang; drizzle with dressing.