Ochre Woods Goulash Recipe

I can't get any of the items for the goulash recipe: spiny shell center (Pikachu needs to Thunderbolt it but he won't listen when I say "Thunderbolt"), sticky fruit (Pikachu won't take it), and a black mushroom (I don't even know what it IS!). And I don't know what the 4th ingredient is. Please help!

Basically, to get the spiny shell open, just try to throw either a flying acorn, or a beach ball at it, and it will fall from the tree. Then keep throwing the Spiny Shell at the ground, until it breaks open into a chestnut.

As for the Sticky Fruit, scroll the camera so that it's pointing at the Sticky Fruit in the tree, then tell Pikachu to use "Thunderbolt" on it. As for the black mushroom, it is called a "Cooked 'Shroom". You have to point at either a "Blue 'Shroom" or a "Sunny 'Shroom" and tell Pikachu to use "Thunderbolt". (If you try to give the item to Pikachu, you'll be unable to tell it to use Thunderbolt on it)

As for the fourth item, you can give Pikachu anything for the 4th item. It could be any item that YOU THINK will be good for the Goulash (Examples: Another one of the three items, a Wild Herb (White Leaf), or any one of the vegetables).