In a medium bowl, combine all the spices, lime juice, and olive oil. Stir to combine.
Add in the chicken breasts and give them a toss to coat. Allow the chicken to marinate for 10 to 30 minutes.
While the chicken marinates, slice the peppers and onions. Set them aside.
Heat a large skillet over medium heat, then add a slight drizzle of olive oil. Add the chicken to the skillet.
Reserve the marinade and add the peppers and onions to the bowl. Toss them around to coat. Then, set the bowl aside.
Allow the chicken to cook undisturbed for about 5 to 8 minutes per side. Take a slight peek under the chicken to check if it has browned. If it is still pale, cook it a bit longer before flipping.
Once the chicken is golden brown, flip it over and do the same on the other side. The less times you move it around, the more crispy and brown it will get.
Once the chicken is browned and cooked to 165 degrees F in the middle, remove it from the skillet onto a cutting board.
Place the peppers and onions into the skillet, allowing any excess marinade to drip off into the bowl. Stir the veggies around and allow them to cook for 5 to 10 minutes, or until the onions become soft and translucent.
Remove the peppers and onions from the skillet and place them into a clean bowl.
Cut the chicken into thin slices.
To assemble, warm corn or flour tortillas in the oven or carefully place them over the open flame of your stovetop. Once warmed through, top them with a few slices of chicken, a scoop of peppers and onions, and all of your favorite toppings: jalapeño slices, black beans, chopped lettuce, and mexican cheese are all great options!
If your tacos are overflowing, double up the tortillas to keep them from falling apart and ripping!