Toss together pork, cumin, salt, lime zest and juice, garlic, 1 teaspoon black pepper, and 1 teaspoon ginger in a medium bowl. Cover and chill at least 30 minutes.

Heat 1 tablespoon coconut oil in a large skillet over high. Working in 2 batches, add pork; cook until browned on both sides, 4 to 5 minutes. Transfer to a plate.

Wipe skillet clean; reduce heat to medium. Add mustard seeds and remaining 1 tablespoon oil; cook, undisturbed, until small bubbles appear on surface of seeds, about 30 seconds. Add onion and chile; cook, stirring occasionally, until softened, about 5 minutes. Add mango and remaining 1 teaspoon ginger; cook, stirring gently, until mango is just tender, 6 minutes. Transfer to plate with pork.

Return 1 cup mango mixture to skillet; add 1 cup hot water. Bring to a simmer over medium-high; cook, smashing fruit using back of a wooden spoon, until slightly thickened, about 3 minutes. Return remaining mango mixture and pork to skillet. Cook, stirring often, until pork is fully coated with mango mixture.

Serve pork mixture over noodles; garnish with scallions and pickled cucumber.