Rinse and dry the chayotes. Slice them down the middle then make a small thin slice on each side to help them lay flat in your baking dish. Scoop out the seed and flesh with a melon baller or spoon to make a shell roughly between 1/2″ to 3/4″ thick. Throw away the seed but keep the scooped out flesh.
Preheat oven to 400° Fahrenheit.
In a food processor, pulse together the chayote flesh pieces with garlic cloves until well minced. Add chopped fish and chives to the food processor. Pulse again until the fish resembles ground meat. Finally, add soy chorizo, soy sauce, and sea salt. Pulse again to mix well.
Remove the blades from the processor and stir in the diced Roma tomatoes. Lightly grease the bottom of a large baking dish with cooking oil.
Slather softened butter around each chayote half, give them a light sprinkle of sea salt. Evenly distribute the filling into all six halves. Cover the dish with foil and bake them in the oven at 400° Fahrenheit for 50-60 minutes until a fork or knife can slide through the chayotes easily.
For this recipe I used Sole, but you can use any other white-fleshed fish available.
Use a baking dish with tall sides if you can.
Since the temperature in ovens can vary, it's a good idea to check for doneness after 45 minutes. The chayotes should be easy to cut with a fork when done.
This recipe would pair well with a small salad or steamed Jasmine rice.