Black Bean Sopes

1 cup instant masa harina, plus more as needed
1/2 teaspoon kosher salt
Hot water
3 tablespoons unsalted butter, at room temperature
Vegetable oil for frying
1 cup Salsa Madre black bean puree (or see note below)
1 avocado, diced
1 cup cherry tomatoes, diced
1/2 lime
Salt and pepper to taste

Combine the masa harina and salt in the bowl of a stand mixer with the beater attachment.  With the mixer on low speed, slowly pour in 3/4 cup hot water until the mixture forms a dough.  It should be moist and tacky but not sticky or dry.  If it's sticky, sprinkle in a little more masa harina and mix to combine; if it's dry, pour in a tablespoon or so more hot water and mix to combine.  

When the dough feels right, turn the mixer to medium-high speed, pinch off a small piece of butter, and drop it into the dough, beating until it disappears before dropping in another piece.  When all the butter is in the dough, turn the mixer to high and beat for another minute, until the masa dough is very fluffy.  Check to see if it has remained slightly tacky but not sticky or dry; beat in more masa harina or water if needed to correct it.

Using a small cookie scoop or large tablespoon, form the masa into eight equal pieces.  Pat each one into a 3-inch disk.

Pour 1 tablespoon of the oil into a large skillet over medium-high heat.  When it shimmers, add as many of the masa disks as will fit without overcrowding.  Cook until very lightly browned, 1 minute per side, then remove to a plate and let cool slightly.  While they're still pretty hot but you can (barely) handle them, pinch the edges of the masa disks all around, turning them to form a rimmed basket shape.

Pour enough oil into the skillet over medium-high heat to come up to 1/2 inch.  When the oil shimmers, add enough of the masa boats (sopes) to fit without overcrowding and fry until crisp, 2 minutes per side.  Transfer to a paper-towel-lined plate.

Mix together diced avocado and cherry tomatoes, squeeze lime half over the mixture, and season to taste with salt and pepper.

Scoop 2 tablespoons of the black bean puree into each of the sopes, then top with avocado and tomato mixture.  Serve while hot.

Makes 8 sopes.

From Cool Beans by Joe Yonan with minor change

Note: If no Salsa Madre on hand, puree 1 1/2 cups cooked or no-salt-added canned black beans, drained and rinsed, with 1/4 teaspoon kosher salt, 1/2 teaspoon ground cumin, and just enough water or bean cooking liquid to help the blender blades turn, then blend until smooth.