In Perfect Harmony (30g)
I'm decided to post this solution since I have received several messages on Xbox Live asking how I did this. It's very simple.
1. Start The Journey (either from scratch, or carry on from your FIFA 17 save file, if you have one). You will play as Alex Hunter, a young footballing prodigy. This is his story.
2. Play through the story as normal, until you can select a European Club to play for, in chapter 4 or 5.
3. Once you join the club, and after playing one game up front alone, the manager will call you into his office and ask you to choose a striking partner, to form a strike duo up front for the club. Pick your player from the available options, it doesn't matter who.
4. Play the games, and pass and assist as much as possible with your chosen strike partner, until the achievement pops. A blue bar keeps track of your progress, both in game, and on the main Journey screen between games. It takes about five - six games to unlock this achievement, depending on the amount of goals and assists shared between Alex Hunter (you) and your chosen partner. It will unlock at the end of a game. However, be aware that...
On your return to controlling Hunter, you can resume where you left off, and bag your 30g.