Heat a large skillet over medium-high and add the olive oil.
Add the chicken pieces and half of the taco seasoning. Cook undisturbed for 2 minutes, flip, then cook 2–3 more minutes, stirring occasionally, until chicken reaches 165°F and is cooked through. Remove chicken to a plate.
Add the drained canned corn to the hot skillet in a thin single layer. Let it cook without stirring 3–4 minutes, then cook an additional 2–3 minutes, stirring occasionally, until edges are golden and slightly charred. Remove corn to the plate with the chicken.
Reduce heat to low and stir in the Alfredo sauce, undrained tomatoes with green chiles, milk, and the remaining taco seasoning. Bring the mixture to a gentle simmer.
Add the tortellini to the sauce, stir to coat, then cover the skillet and simmer 5–7 minutes until tortellini are tender.
Return the cooked chicken and charred corn to the skillet, stir to combine and heat through.
Garnish with chopped cilantro and serve warm.
