To make the steak in the oven, preheat the broiler on high and cook for 6 minutes for medium rare. Squeeze lime juice from half a lime over the steak and allow it to rest for 10 minutes before slicing.
For the cilantro avocado sauce:
Add the avocado, greek yogurt, cilantro, lime, avocado oil, vinegar, and pepper to a food processor or blender. Mix on high for 30-60 seconds or until the sauce becomes smooth and creamy. If you prefer a thinner sauce, mix in water 1 tbsp at a time until the desired consistency is reached.
For the tacos:
Spread a thin layer of avocado sauce on each tortilla. Top with steak, corn, queso fresco, sliced jalapenos, and pico de gallo.