Preheat the oven to 350 degrees F. Line a baking sheet with parchment paper and set aside.
Cut the avocado in half and extract the pit. Then, carefully remove the avocado’s peel, being careful to keep as much of the avocado’s shape intact. Cut the avocado halves into three even slices each. Set aside.
Make the spicy mayo. In a small bowl, stir together the vegan mayonnaise and sriracha. Set aside.
Set up 3 medium, shallow bowls for breading the avocado slices. In the first bowl, whisk together the flour, garlic powder, cayenne (if using), salt, and pepper. In the second bowl, whisk together the non-dairy milk and remaining lime juice. In the third and final bowl, whisk together the chopped pistachios, cornmeal, salt, and pepper.
Place the avocado slices in the bowl with the flour mixture and toss to lightly coat. Then, transfer the avocado slices to the bowl with the non-dairy milk mixture, quickly tossing to coat. Finally, transfer the avocado slices to the bowl with the cornmeal and pistachio mixture, pressing the coating into the exterior of the avocado.
Lay the coated avocado slices on your baking sheet and bake for 20-25 minutes, or until slightly crisp and golden on the outside.
Assemble the sandwich. Cut sections of baguette in half and spread the spicy mayo on both sides. Lay 3 slices of avocado on each bottom half of sandwich. Top the avocado with shredded lettuce before placing the the top half of the baguette on top. Enjoy immediately!
You could easily substitute the finely chopped pistachios with another roasted nut of your choice or even roasted sunflower seeds. Just make sure that they’re very finely chopped.