gluten-free eats

That sounds yummy.
It never would have occurred to me to add corn starch to taco meat, though it makes perfect sense if you want that kind of glossy gravy layer. I sometimes add a couple spoonfuls of instant dried 'refried' beans to my taco meat if I want to thicken juices and don't have time to just simmer it down (or more than a couple spoonfuls, or a whole can of canned beans, drained, if I really need to stretch the taco filling).

My not-from-a-prefab-packet taco seasoning is approximately equal parts by volume Penzey's Arizona Dreaming (a bright Tex-Mex-y blend with cilantro, citrus and cocoa flavors as well as garlic and various peppers), Penzey's Chili Con Carne Spice (or any chili powder blend containing at least cayenne/red pepper, cumin, oregano, garlic, plus a dash of cinnamon OR allspice OR clove; Penzey's has tomato powder too), and Tony Chachere's Creole Seasoning (which is mostly salt, cayenne, and garlic, and those can be substituted in different proportions to make it less salty or less spicy). Plus a splort of tomato something: diced, sauced, paste, prefab salsa, whatever I have on hand. 1-2 tbs total per pound of ground meat. I like to lean more toward the chili seasoning for red meat, more toward the AZ Dreaming for ground turkey. The result is very flavorful, not very hot.

Arizona Dreaming is also good seasoning for fajitas, with equal amounts smoked mild paprika and Sazon Goya (or mix of salt, garlic, paprika, annato, cumin, coriander instead of Sazon Goya if you prefer different proportions; the Sazon is mostly salt).