Thinly slice onion apple (removing stem and seeds) and toss into skillet and stick on low heat, Sprinkle with a tiny bit of salt and give it a splash of apple cider vinegar. Cook for about 10 minutes, stirring occasionally, until the onions and apple are caramelized.
While the onion and apple are cooking, mince garlic and mix together with the peanut butter. When the stuff is just about done caramelizing, stick you bread in toaster (or broiler.. but watch it closely!) and give it a good toast to your darkness preference. When its toasted, smear each piece with equal amounts of the garlic peanut butter and top with the caramlized apple onion mixture.
Sprinkle with a tiny pitch of salt and pepper.