Dice the pineapple into bite-sized pieces and slice the cucumber into half-moons or small cubes. Thinly slice the red onion and jalapeño if you're using it, then chop the cilantro and crumble the feta cheese if you’ve chosen to include it in your salad.
In a small bowl, whisk together lime juice, honey or maple syrup, olive oil, salt, black pepper, and red pepper flakes until well combined.
In a large bowl, combine diced pineapple, cucumber, sliced red onion, chopped cilantro, and jalapeño. Toss these ingredients gently to mix them without bruising the delicate pineapple.
Drizzle your freshly made lime dressing over the salad mixture and toss gently again until everything is evenly coated in that vibrant dressing.
Sprinkle crumbled feta cheese over the top if using it for that extra salty contrast. You can serve immediately or let it chill in the fridge for 15–30 minutes.