Combine water and quinoa in small saucepan over medium-high heat. Bring to a boil, reduce heat to medium, and simmer until liquid has been absorbed, 12 to 15 minutes.
Put sweet potato in small saucepan with enough cold water to cover by 2 while quinoa is cooking. Bring to a boil over medium-high heat and cook until just tender, 3 to 4 minutes. Drain.
Heat 2 teaspoons of the oil in large nonstick frying pan or cast-iron skillet over medium-high heat. Add chicken and cook, stirring occasionally, until starting to brown, about 4 minutes. Transfer to bowl.
Return pan to heat and add remaining 2 teaspoons oil. Stir in onion and jalapeno pepper. Cook, stirring occasionally, 1 minute. Add bell pepper, garlic, and cumin. Cook until vegetables start to soften, 2 to 3 minutes. Stir in peas and reserved chicken and cook 2 minutes. Add quinoa and sweet potato. Cook, stirring frequently, until heated through, 1 to 2 minutes. Remove from heat and stir in cilantro, salt, and black pepper.
Flavor Up Some of the big tastes in Mexican food-cumin, jalapeno, and cilantro as well as garlic, onion, and black pepper-contribute mouth watering zest to this not-so-south-of-the-border dish.