Dice the chicken breast into small, uniform pieces.
In a large skillet over medium heat, combine the chicken, water, chili powder, cumin, garlic powder, and sea salt.
Cook, stirring occasionally, until the chicken is cooked through and the liquid has mostly evaporated, about 7 minutes.
While the chicken is simmering, finely dice the fresh pineapple, jalapeño, and red onion, then toss them in a small bowl with the cilantro and lime juice.
Remove the skillet from the heat and stir in the Greek yogurt until the chicken is thoroughly coated in a creamy, savory sauce.
Warm the flour tortillas in a separate dry skillet over medium heat for 30 seconds on each side until soft and pliable.
Assemble the tacos by spooning the creamy chicken into the tortillas and topping each with a generous portion of the fresh pineapple jalapeño salsa.