Preheat oven to 400°F. Line a sheet pan with parchment paper. Mix the taco seasonings together in a small bowl.
Rub 2 ears of corn all over with softened butter. Season with salt and pepper on all sides. Sprinkle with a few pinches of the taco seasoning blend. Arrange on one half of the sheet pan.
Pat dry the chicken breasts and season both sides with salt. Pat a generous amount of the taco seasoning onto both sides of the chicken breasts, and arrange them on the other side of the sheet pan.
Roast the chicken and corn on the sheet pan for 20-30 minutes. Rotate the corn every 10 minutes for even cooking. Depending on the size of your chicken breasts they may be done earlier than the corn. Test with an instant read thermometer at the thickest part of the breast. When it reaches 160°F, the chicken is done and can be removed to a plate to rest.While the chicken and corn are cooking, wash and dry the raw ear of corn and prep the rest of the salsa ingredients.
Give the chicken and corn at least 10 minutes to rest, then shred the chicken with two forks or shredding claws if you have them. Set aside. Use a sharp knife to cut the corn kernels off both ears of roasted corn and the 1 ear of raw sweet corn.
In a medium bowl combine the corn kernels with the additional salsa ingredients, finishing with the squeeze of lime juice and a few pinches of salt and pepper to taste.
Salsa can be served chilled or at room temp.
Heat the tortillas in a bare skillet over medium heat or remove the parchment paper from the sheet pan and let them hang out there for a few minutes in the oven as it cools down.
Assemble your tacos and enjoy!