Sautéeing: Heat the oil in a pan over very low heat. Add garlic, bija, half the salt, cubanela, and habanero to the oil, cook stirring occasionally until the pepper is cooked through, taking care that it does not burn. Stir in the shrimp, parsley, and ⅓ cup water, and cook until the shrimp have turned pink. Season with salt to taste.
Serving: Serve the corn on a bed of chenchén, and accompany with slices of chilled avocado and garnish with lime wedges.
Habaneros are fairly spicy, so how spicy you want this dish will depend entirely on you. I can tolerate very spicy food, so I may use a whole one, you should start with a quarter, and add more until you find your comfort level. Discard the seeds if you want it even less spicy.