• Marinate shrimp: Combine the fajita seasoning blend with the lime zest, lime juice, olive oil, and water in a resealable plastic bag. Squeeze the bag to mix well. Add the shrimp and squeeze the bag to distribute the marinade over the shrimp. Squeeze all of the air out of the bag, seal well, and refrigerate for one hour (do not marinate any longer because the acid in the lime juice can actually "cook" the shrimp).
  

Cook fajitas:

• Cook vegetables: Using a large skillet (cast iron preferred), heat over high heat with avocado oil. When oil begins to soak, add sliced peppers and onions. Stir well to coat in oil and then allow the vegetables to sear, only tossing every so often to prevent burning. Once the peppers and onions have seared nicely but are still pretty firm, transfer them to a separate bowl.
  
• Cook shrimp: Add marinated shrimp along with all of the marinade to the hot pan. Use tongs to place the shrimp so that they all have contact with the bottom of the pan. Again, only stir every so often to prevent burning. You want the outside of the shrimp to sear without overcooking them, if possible. Once the bottoms of the shrimp are bright pink, flip them and allow the other side to sear.
  
• Combine: Once the shrimp are cooked through, reduce the heat to low, add the seared vegetables, toss to combine, and serve them sizzling hot.