Combine cajun seasoning, ancho chili powder, minced lemongrass, ground ginger, and vegetable oil in a small bowl. Mix until well incorporated.
Add the shrimp to the bowl and coat with the marinade. Marinate for 10 minutes.
While the shrimp is marinating, toast the bread. Smear butter on one side of the bread and toast until golden brown (~5 minutes). The timing will vary based on the thickness of your bread.
Heat a large nonstick pan over medium high heat. Add in the shrimp and marinade. Cook the shrimp for ~1 minutes on each side.
Next add in the sliced garlic and cook for 20 seconds.
Lastly, add in the butter and sake. Cook for another minute until the butter melts and the alcohol has burned off. Remove the shrimp from the heat.
Now it's time to assemble your toast. Spoon the shrimp over the toasted bread. Finish it off with a squeeze of lime juice and minced cilantro.