Combine 1 tablespoon soy sauce, 2 teaspoons cornstarch, sake, and sesame oil in a large bowl. Add pork and toss to coat. Combine 1 remaining 1/2 teaspoon cornstarch & 1/2 teaspoon soy sauce and stock in a small bowl.
Heat wok or large skillet over high heat. Add canola oil; swirl to coat. add garlic and ginger. stir fry 30 seconds or until fragrant. Add pork mixture to pan; stir fry 3 minutes or until browned. add bell pepper, onion, and asparagus; stir fry 3 minutes until crisp tender. Add stock mixture and salt; bring to a boil. Cook 2 minutes or until sauce is slightly thickened.
Prepare rice according to package instructions. Serve pork mixture over rice.