Combine items in inventory (a la LucasArts)

I guess this is more trying to figure out the best way to think about the problem.

I'm halfway through a project where the character can combine items with each other. Each combination, if possible results in a different reaction from the character and a unique result (sometimes a new object, sometimes changes on the original object etc)

If the combination is impossible the character can say the generic "Not sure how to do that" or sometimes a more specific reply about why its impossible to combine the 2 objects.

The way I do it so far is compare if the names of the objects are "acceptable" using a generic list

 combinationsList.Add("Ambien Pills, Mug with tea satchet");
     combinationsList.Add("Ambien Pills, Mug with cold water");
     combinationsList.Add("Ambien Pills, Mug with hot water");
     combinationsList.Add("Ambien Pills, Mug with sleeping pills");

If the combination is in the list then sort the result between the two objects:

 if (x.basicProperties.objName == "Ambien Pills"){
         //Mug
         if (y.basicProperties.objName == "Mug"){
             playerInteractions.SaySingleThought("Added a couple of pills to the mug.");
             audio.PlayClipAtPoint(x.customAudioClip01, x.transform.position);
             
             y.basicProperties.objName = "Mug with sleeping pills";
             y.basicProperties.lookAtDescription = "It has a couple of sleeping pills.";
         }
         //Mug with tea satchet
         else if (y.basicProperties.objName == "Mug with tea satchet"){
             playerInteractions.SaySingleThought("Added a couple of pills to the mug.");
             audio.PlayClipAtPoint(x.customAudioClip01, x.transform.position);
             
             y.basicProperties.objName = "Mug with tea satchet and sleeping pills";
             y.basicProperties.lookAtDescription = "A mug with sleeping pills and a tea satchet.";
         }

This is doing exactly what I need but I think it will get messy once I have a lot of objects.

After thinking a while this is how I think I should do it:

• Each object adds himself to an array

• In the editor, per object, I have the option to "add" objects" that I want the selected object to interact with (like a drop down list from the array I created).

• Once I added a object combination to the selected object I can write the custom code that will be executed when the combination happens.

This way I could just select an object to see what are the current valid combinations and quickly add more.

Now I don't know how I go about doing the drop down list from the array in the editor. And how would I be able to write custom code in the editor that will run in game for each interaction?

Hope the question is clear, thanks in advance!