Core and seed the pepper and peel the jicama. Cut the pepper, zucchini, and jicama into thin strips.
In a small saucepan, bring the lemon juice to a boil over medium heat. Boil 2-3 minutes, until juice is reduced to 1 tablespoon. Remove from heat and let stand 1 minute. Stir in the butter until it is melted and incorporated. Set aside.
Heat the oil in a non-stick skillet. Add the pepper, zucchini, jicama, and turkey and saute for 2-3 minutes.
Add the water and saute another 3-4 minutes, until the vegetables are tender.
Drizzle with lemon butter. Season with salt and pepper to taste and toss to blend.
Cut pitas in half cross-wise and stuff with vegetable/turkey mixture.