A "bespoke" suit is a custom-made suit. Every detail will be bespoken: style, cut, fabric. It will be drafted only for you, and hand-made down to the button-holes. The tailor takes your individual measurements, makes the cut etc. Then there will be a first fitting, were you check the fit, or come up with new choices. At the second fitting, the suit will be almost finished, it's just about details.
The whole Boateng family seems to be skilled. I don't want to forget to mention his cousin in New York City: Nana Boateng, who designs suits too (found an interview here).