Preheat the oven to 350 degrees F.
Pour the salt into 2 cups lukewarm water. Mix the arepa cornmeal slowly into the salted water until smooth, let stand for 5 minutes. Divide into 4 equal parts and shape the dough into a flat disk.
Heat a griddle or pan over high heat. Place the arepas on a hot griddle or pan and cook until small brown spots appear, 5 to 7 minutes on each side. Finish the arepas in the oven for 15 to 20 minutes.
Insert a butter knife into the arepa edge, cut halfway around the arepa and pop it open for stuffing. Begin with cheese as a base, and then layer the salmon on top. Sprinkle with capers and top with sliced avocado. Repeat for the remaining arepas.
Arepa cornmeal (flour) can be found in Hispanic specialty stores or online.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.