The 24-year-old Malawi-born attacker scored 19 goals in 31 appearances for Evo-Stik Division One South outfit Gresley FC to earn his move to the National League midway through the 2016-2017 campaign.
The in-demand winger, who was welcomed by assistant manager Karl Hawley (pictured), had previously enjoyed a trial spell in Sky Bet League 2 with Grimsby Town ahead of his eventual move to Solihull.
Mwanyongo is United's sixth new signing of the closed season, following on from the recruitment of goalkeeper George Willis, defenders Bradley Beatson and Jack Cowgill, midfielder Jamie McGuire and striker Tyrell Waite.
Reflecting on Mwanyongo’s arrival, United boss Adam Murray said: "Pearson went to a League 2 club on trial during last season, but Solihull pipped them to his signature.
"It did not quite work out for him at Solihull, but he is hungry to prove a point. He's an exciting winger who wants to go past people and create and score goals.
"Pearson is a skilful player who endeavours to get people off their seats and it gives us another attacking threat."
Who will be next? Stay tuned to bostonunited.co.uk and the club's Twitter and Facebook pages throughout the summer months.
Updated 11:20 - 22 Jun 2017 by Craig Singleton