We did this activity when I was a laurel a few years back.
Each Young Man and Young Woman invited a favorite teacher to a Teacher Appreciation Dinner. It was a lot of fun. “Favorite Teachers” consisted of anything from Elementary/JR High/High School teachers, to Piano Teachers, Karate Teachers, Primary Teachers, Home Teachers, a Grandparent, etc.
Teachers were given invitations 1 month in advance, along with RSVP instructions. Youth were encouraged to follow-up with teacher if no response received within 2 weeks of activity, to allow time to invite replacement, if needed.
As the teachers arrived, the youth welcomed them with name tags, and they were seated next to the youth that invited them.
I did NOT live in a predominately LDS community, so we tried to make the evening as “light” as possible. We began by welcoming everyone out, and then had a blessing on the food. The dinner was spaghetti. Each youth had a chance to serve their guest. Once everyone got settled, each youth took a turn to stand and introduce their guest, and explain why he or she was their favorite teacher.
The Young Men’s President followed up the evening, by stating that he was sure there might be questions about our religion by some of our visitors. He directed any who were curious to a table at the back of the room (which held missionary pamphlets, pass along cards, etc.). This was a nice touch, as teachers did not feel pressured to hear the gospel in any way. It allowed things to stay comfortable. We then thanked our teachers for coming, and had a closing prayer.