Place frozen peas in a colander and rinse with cold water to thaw; drain and pat dry.
In a large saucepan heat oil over medium-high heat. Add cumin and crushed red pepper (if using); cook and stir 30 seconds or until fragrant. Stir in peas. Cook 3 minutes, stirring occasionally. Add cilantro; cook and stir 30 seconds more. If desired, season to taste with salt.