Drizzle 2 tbsp. of oil over the chicken pieces, and season with salt and pepper, cumin, coriander powder and fennel powder. Grill chicken in the pan for 4-6 minutes or until golden brown. This may be done in batches so the griddle pan is not overcrowded.
In the same pan, add the remaining oil and over a high heat, add the onion, and cook for 5 minutes before adding, salt and pepper and then returning the corn.
Pour this corn and onion mixture into a large bowl, and add the tomato, avocado, feta and coriander leaves and lime.
Mix the sour cream with the Tobasco and extra lime.
Heat up your tortillas in the oven for two minutes. Evenly spread the sour cream on the tortillas, and then add the cooked chicken, corn salsa and spinach. Wrap tightly.