Counting Sandwich Orders!

Hi all, and please forgive me for joining just to post a single question. I've been working on something very high-end, as you can tell from the thread title. I've made my little spreadsheet do almost everything I need, but I'm stuck on this:

I want a cell to include all of the names from a column A who have chosen a certain selection from columns B, C and D.

This table should explain it:


So my first row in the 'order' sheet will read "Cheese on Brown with Butter" in the first column, and the second column will read "John, Ringo"

Obviously I'd then go on to make a row for every sandwich option, with the second column returning the names of those who have made that choice.

I hope that's explained well enough, and I really would appreciate a pointer as to the formula I'm trying to write. Until this point I've worked things out, and I can display nice list of orders, but the final "who ordered what" step has got me stumped hwell:

Many thanks for any help.

Steve

Assuming that you have your orders in H2:J7, put this array formula in K2, copy down all rows and across as many columns as you think you might need

=IFERROR(INDEX($A$1:$A$8,SMALL(IF(($B$1:$B$8=$H2)*($C$1:$C$8=$I2)*($D$1:$D$8=$J2),ROW($A$1:$A$8)),COLUMN(A1))),"")

Thank you so much. I would never have worked that out in a million years. I shall however work through it so that I understand what's going on.