Prepare the pineapple: reserve 1 cup of the pineapple and chop the remaining 1 cup into small dice; set the diced pineapple aside.
Make the teriyaki sauce: in a blender combine the reserved 1 cup pineapple, the knob of fresh ginger, 2 cloves garlic, 1/2 cup soy sauce, 3 tablespoons brown sugar, and 1/2 teaspoon sesame oil; puree until smooth.
Mix herbs and pineapple: mince the leaves from the 1 sprig fresh mint or basil and stir into the diced pineapple in a small bowl; set aside for topping.
Heat the pan: warm a large sauté or frying pan over medium-high heat and add 1 tablespoon olive oil, swirling to coat the pan.
Sear the salmon: when the oil is hot, add the 4 salmon fillets skin-side down if applicable and cook 2–3 minutes per side until a golden crust forms and the interior is just barely translucent.
Add the sauce: pour the blended pineapple teriyaki sauce into the pan and simmer for about 1 minute, spooning the sauce over the salmon to glaze.
Finish and serve: top each fillet with the diced pineapple and minced mint or basil, then serve immediately.