Preheat the oven to 400°. In a medium bowl, mix 1 tablespoon of the yogurt with the garlic, garam masala and curry powder. Add the chicken strips and stir until they are thoroughly coated with the yogurt-spice mixture.
In a large nonstick skillet, heat the vegetable oil. Add the sliced jalapeños, red onion and coated chicken strips, season with salt and pepper and cook over moderately high heat, stirring, until the chicken strips are just white throughout, about 5 minutes. Remove the skillet from the heat and let stand for 1 minute to let the chicken, jalapeños and red onion cool slightly. Fold the remaining 1 cup plus 3 tablespoons of yogurt into the chicken, jalapeños and red onion until well combined.
Heat the pita breads in the oven, about 30 seconds. Set the pitas on plates and top each one with a lettuce leaf, tomato wedges and cucumber slices. Spoon the chicken in yogurt sauce on top and serve right away.
Notes: One serving 416 calories, 8 gm total fat, 3 gm saturated fat, 51 gm carb.