1 tablespoon bottled minced ginger
1 tablespoon bottled minced garlic
2 tablespoons lower-sodium soy sauce
1 1/2 teaspoons dark brown sugar
1/2 teaspoon crushed red pepper
1 tablespoon dark sesame oil
1 pound presliced stir-fry meat (such as flank or boneless sirloin steak)
8 green onions, cut into 1-inch pieces (white and light green parts only)
4 cups bagged baby spinach leaves
1 tablespoon sesame seeds