Preheat the oven to 400 degrees (or if using an air fryer 375 degrees)
Peel and cut the butternut squash into 1 inch cubes.
Slice the onion into slivers.
Cut the red pepper into bite-sized peices similar to the butternut squash.
Place the cut butter nut squash, onion, and red bell pepper into a bowl.
Add the juice of 2 limes and 1 Tablespoon of taco seasoning.
Using a spoon or your hands, toss the vegetables with the lime juice and taco seasoning.
If time permits, refrigerate to allow the flavors to develop for an hour, or overnight.
Pour vegetables onto a baking sheet, lined with parchment paper or a silicone baking mat, and roast for 30 minutes.
If using an air fryer, place vegetables on the aor fryer pan in a single layer.
Cook at 375 for 15 minutes, tossing the vegetables half way through cooking.