You can certainly use a packet of taco seasoning for this, but I chose to use my homemade taco seasoning here.
I prefer to use lean ground beef (90/10) specifically so I don't have to drain as much fat off. You can easily substitute with ground chicken or turkey if preferred.
To give this casserole a little kick feel free to add some diced jalapenos, red pepper flakes, spicy salsa, or toss in a can of green chiles to the meat mixture.