Preheat your oven to 375°F.
Place the chicken breasts in a baking dish and season them with salt and taco seasoning.
Bake the chicken for 35-40 minutes, then let it cool for about 5 minutes.
Use two forks to shred the chicken and return it to the baking dish with its juices.
In a medium bowl, combine the diced onion, jalapeños, garlic, cilantro, lime juice, and salt.
Toss everything together to make the salsa.
Warm up the corn tortillas on a skillet until they’re soft and pliable.
Keep them warm in a tortilla warmer or covered in a kitchen towel.
Assemble the tacos by filling each tortilla with shredded chicken, onion salsa, Cotija cheese, and pickled red onion.
Serve immediately!