Angus Buchan shot to international attention in the wake of the book and film Faith Like Potatoes. He continues to work as an international evangelist, traveling from his base in South Africa to run rallies in rural communities and to work with local leaders. He is perhaps best known for The Mighty Men Conference, which gathers over 200,000 Christian men. In addition, Angus and his wife run a children's home for 25 abandoned orphans and a Christian school with over 200 pupils.

A Mustard Seed offers readings for the full calendar year, with a Scripture passage for each day, a meditation (often including an arresting anecdote), and a short prayer.