How to add textures on top of textures? I'm trying to create some sushi.

I've got this but I don't understand the UVWrapping as I need to almost decal some ingredients onto the rice texture.



As you can see, I went to edit mode (&#8633; Tab) then selected the top and bottom of the sushi... I added a texture in that texture tab on the right, and then selected that texture from the UV editor... The rice appeared and I positioned the circles accordingly.

I then hit A to select the entire sushi roll and then de-selected the top and bottom... In the UV editor, I then applied my sushi wrap texture.

Now what? How do I go and apply a texture of sushi ingredients on top of this roll?
After adding a material, add two textures. The texture(s) lower on the list will be applied over the previous texture(s):