To improve the chances that he could make a definitive move on you, you could start things off by opening conversation with him.
Being that he works at the Supermarket, you could start a conversation with him next Friday by using the Supermarket as an opening topic.
Using your environment or location is often an easy way to open up conversation with someone that you don’t know.
Ask him a question in relation to the Supermarket.
Observe his body language as the both of you converse.
He may give away the fact that he either likes you or doesn’t while he is talking to you.
If he likes you, look for a lot of sustained eye contact and smiling.
Observe whether he tries to check you out sneakily by quickly looking you up and down from time to time.
Observe whether he gets really fidgety with stuff by either playing with his hair or clothing a lot, or even fidgeting around with the trolleys.
It’s best to go to the Supermarket next Friday and do this.
If you choose not to go there for a while, you run the risk of never trying to do something.
You will just come back after a while, hoping that he somehow magically notices or remembers you and makes a move.
However, that is unlikely to happen.
His possible recollection that you have stared at him in the past may fizzle out over this period of time and any window of opportunity you may or may not have had with him may pass you by.
At this time, he may or may not be interested.
By making this move next Friday to open a conversation with him at the Supermarket, you will be able to get a better idea on whether he is interested in you or not by observing his body language.
It is best to try doing this first before moving on.
This way, you don’t leave anything to chance.