Heat olive oil in a large skillet over medium heat; cook and stir quinoa and onion in the hot oil until onion is translucent, about 5 minutes. Add garlic and jalapeno pepper to quinoa mixture and cook until garlic is fragrant and slightly softened, 1 or 2 more minutes.
Mix undrained can of diced tomatoes with green chiles, taco seasoning mix, and chicken broth into quinoa mixture. Bring to a boil, reduce heat to medium-low, and simmer until liquid has been absorbed, 15 to 20 minutes. Stir in cilantro.
