It's an extra stir fry and pickup as indicated in the rules:
The first time you pick up a Green Pepper on a turn, you immediately perform one additional stir fry action and then pick up another face up ingredient (if any).
If you pick a Green Pepper you get 3 picks in the round (backed up by these entries under Additional Clarifications):
* If you pick up a Green Pepper and a Garlic in the same turn, you will get two bonus stir fry actions (and pick ups). You must announce which you are performing first so that your opponents know which pick-up is for yourself and which is for another player.
* If you have two additional stir fry actions, you must perform them one at a time. Stir once, then pick up one ingredient; repeat the process for your second action.
The phrasing "you will get two bonus stir fry actions (and pick ups)," clarifies that both the stir fry and pick up are part of the bonus. Of course, that quote contradicts the word immediately
in the first rule quote. If you performed additional stir fry and pick-ups immediately, there would never be any confusion to be clarified by the second rule quote - you would pick up the visible Green Pepper, stir fry and pick up an extra card, then pick up the Garlic, and then stir fry and pick up an extra card to give to an opponent. Because you indicate both cards you want before picking up any cards, I suspect that the word immediately
shouldn't be in the first rule quoted, as your extra stir fry action could cause your second declared pickup to become unavailable.
Now that you have me thinking about Green Peppers and extra stir fry/pick up actions though... if I pick up a Garlic and *whatever non Green Pepper card*, I will do an additional stir fry and pick up. If a Green Pepper comes up, I would have to take it (assuming that the additional actions conform to the regular pick up rules?) and give it to an opponent. Would the first rule quoted above then kick in, giving me an additonal stir fry and pick up action (as it would be the first time I picked up a Green Pepper on the turn)?