Heat a large cast iron skillet over medium-high heat, once hot, add 2 tsp of avocado oil and shrimp.
Add the shrimp, garlic powder and ¼ tsp kosher salt. Cook on the first side for 1-2 minutes until nicely browned, then stir the shrimp together. This should create a nice browning on the bottom of the pan. Once the shrimp is almost all pink, remove to a plate and set aside.
Add in another 2 tsp avocado oil. Add in the sliced zucchini and cook for 1-2 minutes until nicely browned.
Next add in the sliced bell peppers and sliced tomatoes. Combine the balsamic, remaining avocado oil and remaining salt. Drizzle this around the pan and scrape off the brown from the bottom of the pan. Cook for a few minutes only so the vegetables are still slightly crunchy.
Add the shrimp back into the pan and stir well. Enjoy hot.