Place the lemon juice, olive oil, oregano, coriander and garlic in a blender and blend until smooth.
Put half the marinade and chicken in a gallon bag and refrigerate.
Spread the marinade well to make sure the chicken is coated.
Refrigerate for 1 to 4 hours.
Remove the chicken and pat dry.
Sprinkle with salt and pepper (don't skimp on the pepper!).
Heat oil in an electric skillet at medium-high heat.
Cook the chicken for 4 minutes.
Flip the chicken, and reduce the heat to medium and cook until the chicken is cooked through (about 6 minutes).
Remove chicken from heat and allow to cool for 5 minutes for juices to redistribute.
Chop the chicken into 1/4-inch chunks and place in a large bowl.
Add the other half of the marinade that you didn't use to marinate the chicken originally.