Prepare the filling:

Chop the vegetables.
Heat some olive oil in a pan and add the chopped vegetables. Sauté them.
Add the ground chicken and cook it over high heat.
Season with salt, paprika powder, and roasted cumin powder.
Roughly chop the garlic, add it to the pan, and mix well.
Once the chicken is cooked thoroughly, turn off the heat and let it cool.
Prepare the salsa:

Finely chop the onion, green chilies, and tomato, and mix them together.
Add fresh parsley, salt, lemon juice, and Tabasco sauce. Mix well.
Prepare the guacamole:

In a bowl, mash the avocado.
Squeeze in lime juice and add salt to taste.
Stir in sour cream until well combined.
Assemble the tacos:

Grate the lettuce leaves.
Take a taco shell and fill it with shredded lettuce, the chicken filling, salsa, and guacamole.
Serve:

Mexican Chicken Tacos are ready to be served!