Bring a large pot of water to a boil. Add chicken; cook until an internal thermometer inserted into the center reads at least 165 degrees F (74 degrees C), 15 to 20 minutes. Drain and cool until easily handled; cut into cubes.
Mix chicken with coriander in a bowl.
Bring a large pot of lightly salted water to a boil. Cook angel hair, stirring occasionally, until tender yet firm to the bite, 4 to 5 minutes. Drain.
Heat olive oil in a large skillet over medium-high heat. Add half the chicken; cover and cook until lightly browned, about 1 minute. Transfer to a plate. Repeat with remaining chicken.
Combine 1 1/2 cup broth and snow peas in the same skillet; cover and cook until just tender, 3 to 4 minutes. Return chicken to the skillet. Stir in remaining 1/2 cup broth and lemon juice; cover and simmer until flavors combine, 3 to 5 minutes. Season with salt and pepper.
Serve chicken over pasta. Garnish with chopped scallions.