In a saucepan, combine the pineapple juice, soy sauce, hoisin sauce, brown sugar, cornstarch, and garlic. Simmer over low heat, stirring occasionally, for 5 to 10 minutes, allowing the sauce to thicken to your liking. It should be thick enough to coat the back of a spoon.
At the same time, season the chicken cubes with salt, pepper, and garlic.
In a large pan over medium heat, add in the olive oil and the chicken. Leave the chicken undisturbed for around 2 minutes or until a golden crust has formed before flipping it.
Once the chicken as been cooked through and golden, add in the pineapple and cashews. Stir to combine.
Add in the sauce and stir to combine before serving.
One pot: you can cook the chicken, pineapple, and cashew first then set it aside, cook the sauce in the same skillet, and add the chicken back to the sauce.