Toast cumin and fennel seeds in a small dry skillet over medium heat until fragrant and beginning to brown, about 2 minutes. Finely grind in a spice grinder or with a mortar and pestle.
Toss chicken with 1 1/2 teaspoons of the spice mixture and salt in a bowl. Heat 1 tablespoon oil in a large nonstick skillet over medium-high heat; add the chicken and cook, stirring frequently, until browned, and just cooked through, 3 to 4 minutes. Remove to a plate.
Reduce heat to medium and add the remaining 1 tablespoon oil, onion, garlic, chile and ginger; cook, stirring, until softened, about 2 to 3 minutes. Add asparagus, sprinkle with the remaining spice mixture and cook, stirring, for 2 minutes. Remove asparagus to bowl. Stir in coconut milk and simmer for 2 minutes. Return the chicken and any accumulated juice to the pan and cook until the chicken is heated through. Return asparagus to pan and cook just until asparagus is crisp-tender, about 2 minutes.