Sopa Fría de Aguacate con Sal de Gusano

Ingredients

Equipment Needed

• •High-powered blender (a Vitamix or equivalent will give the smoothest result)
• •Fine-mesh strainer (optional, for an extra-silky texture)
• •Glass or ceramic container with a flat surface for chilling
• •Dry comal or small skillet for toasting pepitas
• •Chilled serving bowls (barro negro if you have them)

Instructions

1. 1

   Prepare the avocados

   Halve each avocado lengthwise, remove the pit, and scoop the flesh into a large bowl. You need them ripe. Not firm, not brown, not the ones that were hard yesterday and you're hoping will be ready today. Press the skin near the stem. If it gives gently and the flesh underneath is bright green, that's the avocado you want. If it's brown and stringy inside, throw it out. No amount of lime will save a bad avocado.

   Hass avocados from Michoacan or the Sierra Norte de Puebla are the standard. The small, black-skinned ones with the creamy, almost buttery flesh. Do not use the large, watery Florida avocados. Different fruit, different dish.
2. 2

   Blend the soup base

   Add the avocado flesh to a blender with the cold chicken broth, cold water, lime juice, cilantro, white onion, garlic, chile serrano, and kosher salt. Blend on high for a full minute until completely smooth and the color is a uniform pale green with no streaks. The broth must be cold. Warm broth oxidizes the avocado and you'll end up with a gray soup that tastes fine but looks like you didn't care. Cold ingredients, cold blender jar. That's how this stays green.

   If you have homemade chicken broth in the refrigerator with a cap of yellow fat on top, skim the fat off but don't throw it away. That broth will have body that boxed broth never will. The gelatin in a real broth gives the soup a richness that makes the avocado feel substantial, not watery.
3. 3

   Add the crema and mezcal

   With the blender running on low, add the Mexican crema and the two tablespoons of mezcal espadín. Blend for fifteen more seconds. The crema rounds the texture, gives the soup a silky weight on the tongue that avocado alone can't achieve. The mezcal is subtle here. You're not making a cocktail. You're adding a thread of smoke that will meet the sal de gusano at the table and remind the person eating it exactly where this dish comes from. Taste now and adjust salt. It should taste clean, bright from the lime, faintly green from the cilantro, with the mezcal barely whispering underneath.

4. 4

   Chill the soup

   Pour the soup into a glass or ceramic container, press a piece of plastic wrap directly onto the surface to prevent oxidation, and refrigerate for at least one hour or up to four hours. The soup must be cold. Not room temperature, cold. The flavor tightens when it's chilled. The lime sharpens. The avocado becomes more like cream and less like puree. Do not skip this step and serve it warm from the blender. That is a smoothie, not a soup.

   The plastic wrap pressed directly onto the surface is not optional. Avocado oxidizes fast. Exposed to air for an hour in the refrigerator, the top layer turns brown. The flavor isn't ruined but the color is, and this dish depends on its pale green for visual impact.
5. 5

   Toast the pepitas

   While the soup chills, heat a dry comal or small skillet over medium heat. Add the pepitas in a single layer and toast, stirring often, for three to four minutes until they start to pop and turn golden with brown spots. They go from toasted to burned in seconds, so stand there. Move them off the hot pan immediately onto a plate. Sprinkle a pinch of sal de gusano over the warm pepitas and toss. Set aside.

6. 6

   Serve and finish at the table

   Ladle the cold soup into chilled bowls. Drizzle a thin stream of olive oil or avocado oil across the surface. Scatter the sal de gusano-dusted pepitas over each bowl. Add a few thin slices of fresh chile serrano if you want, a scattering of cilantro leaves, and set a lime wedge on the rim. At the table, pass more sal de gusano and a small jícara of mezcal so each guest can add a splash and an extra pinch to their own bowl. The sal de gusano should hit the tongue as a finishing salt, not a seasoning cooked in. That's the Oaxacan move: the smoke and the earth and the chile arrive at the moment of eating, not before. Recetas probadas y garantizadas.

Chef Tips

• •Sal de gusano is not optional, it is the identity of this dish. Without it, you have a fine cold avocado soup. With it, you have an Oaxacan cold avocado soup. The difference matters. Look for it at Mexican specialty markets, Oaxacan import shops, or online vendors who source directly from Oaxaca. Guelaguetza brand from Los Angeles is reliable if you cannot get market sal de gusano.
• •The chicken broth must have body. If you press your thumb and forefinger together after dipping them in the chilled broth and they stick slightly, it has enough gelatin. Boxed broth will work in a pinch, but reduce it by half first and chill it again so it concentrates. Watery broth makes watery soup.
• •Use mezcal espadín, not a smoky wild agave variety like tobala or madrecuixe. Espadín's smoke is moderate and round. A heavily smoky mezcal will overpower the avocado and compete with the sal de gusano instead of working alongside it. Save the expensive bottles for sipping.
• •If your avocados are not perfectly ripe, do not make this soup today. Make something else. This dish has nowhere for imperfect avocado to hide. Every flaw, every fibrous strand, every brown spot, shows up in the texture and the color.

Advance Preparation

• •The chicken broth should be made at least one day ahead, chilled, and skimmed of fat. A broth with good gelatin content is essential for the body of this soup.
• •The soup can be blended and chilled up to four hours ahead with plastic wrap pressed directly onto the surface. Past four hours, the color begins to dull even with the lime and the wrap. This is a same-day preparation.
• •The pepitas can be toasted and dusted with sal de gusano up to two hours ahead. Store them uncovered at room temperature so they stay crisp.

Frequently Asked Questions

Nutrition Information

1 serving (about 305g)