In a large skillet, preferably cast iron, heat oil over medium-high. Add 1 cup onion, garlic, and a pinch of salt. Cook, stirring occasionally, until softened and just beginning to brown, 3 to 4 minutes. Add chicken, cumin, coriander, salt, and pepper. Cook, breaking up meat with the back of a wooden spoon, until browned and crumbly, 5 to 6 minutes. Stir in tomato paste, chipotle, and broth. Bring to a simmer, reduce heat and cook until most of the liquid has evaporated, about 1 minute. Keep warm.
Stir together remaining onion, tomato, jalapeno, lime and cilantro. Season with salt and pepper. To serve, fill taco shell with meat mixture and pico de gallo and top with cheese, lettuce, and sour cream.
In a large skillet, preferably cast iron, heat oil over medium-high. Add 1 cup onion, garlic, and a pinch of salt. Cook, stirring occasionally, until softened and just beginning to brown, 3 to 4 minutes. Add chicken, cumin, coriander, salt, and pepper. Cook, breaking up meat with the back of a wooden spoon, until browned and crumbly, 5 to 6 minutes. Stir in tomato paste, chipotle, and broth. Bring to a simmer, reduce heat and cook until most of the liquid has evaporated, about 1 minute. Keep warm.
Stir together remaining onion, tomato, jalapeno, lime and cilantro. Season with salt and pepper. To serve, fill taco shell with meat mixture and pico de gallo and top with cheese, lettuce, and sour cream.