Remove the skin and core from the pineapple. Cut into bite-sized chunks, about 3/4-inch pieces. If using pre-cut pineapple, ensure pieces are uniform in size.
Wash and dry the cucumbers. Leave the skin on for extra texture and color. Cut into half-moon slices or dice into chunks similar in size to the pineapple.
Slice the onion thinly using a knife or mandoline. To mellow the flavor, soak the slices in cold water for 10–15 minutes, then drain and pat dry.
Roughly chop the cilantro and mint, keeping the pieces fairly large.
In a small bowl, whisk together the lime juice, honey or maple syrup, olive oil (if using), salt, pepper, and chili flakes. Adjust seasoning to taste.
In a large bowl, gently toss the pineapple, cucumber, onion, and herbs. Pour the dressing over and mix carefully to coat without crushing the ingredients.
Refrigerate for at least 30 minutes to let the flavors meld. Serve chilled.