Wash and dry produce.

Trim and thinly slice scallions, separating whites from greens. Peel and grate garlic. Trim and thinly slice cucumber.

Heat a drizzle of oil in a large pan over medium-high heat. Add pork*, scallion whites, garlic, salt, and pepper. Cook, breaking up meat into pieces, until pork is browned and scallion whites are softened, 2-4 minutes.

Add umami ginger sauce, ketchup, Sriracha, and half the sesame seeds. Cook, stirring, until sauce is thickened and pork is cooked through, 1-2 minutes more. Taste and season with salt and pepper if desired. Remove from heat and cover to keep warm.

In a large bowl, combine carrots, cucumber, scallion greens, vinegar, remaining sesame seeds, ¼ tsp sugar (½ tsp for 4 servings), and a pinch of salt.

Halve and toast buns.

Fill buns with pork mixture and as much cucumber-carrot salad (draining first) as you like. Divide sloppy joes between plates and serve with any remaining cucumber-carrot salad on the side.