Choose an interesting topic.
Arrange a date with the Minister or another church leader.
Invite half a dozen or a dozen friends round for morning coffee, afternoon tea, evening nibbles, or arrange to meet in a coffee shop, or a local hostelry, in order to discuss the chosen topic. Use suitable “Grill the Vicar” invitation cards.
On the day, the Minister gives a 10 minute introduction to the topic and then referees the discussion.
You can start by inviting all Christians – in time you will be confident to invite not-yet-Christian friends too. It all depends on the topic and what you want to achieve for the occasion.