Ingredients:

  • 1 cup packed fresh cilantro leaves (stems mostly removed) — about 20–30 g
  • 1 small jalapeño (stem removed; seeded for mild, leave seeds for more heat) — about 15–20 g
  • OR 1 tablespoon aji amarillo paste (15–20 g) in place of or with jalapeño
  • 1–2 garlic cloves, peeled (6–10 g)
  • 1/2 cup mayonnaise (120 ml / ~115 g) — use regular or light
  • 1/2 cup plain Greek yogurt (120 ml / ~120 g) — or sour cream for richer flavor
  • 2 tablespoons fresh lime juice (30 ml) — about 1 lime
  • 2 tablespoons extra-virgin olive oil (30 ml)
  • 2 tablespoons grated Parmesan cheese or crumbled queso fresco (10–15 g) — optional but recommended
  • 1–2 teaspoons kosher salt (5–10 g), to taste
  • 1/4 teaspoon freshly ground black pepper (optional)
  • 2–4 tablespoons cold water (30–60 ml) to thin, as needed

Instructions:

  1. Prep ingredients: wash and roughly chop cilantro and chile; peel garlic; juice lime.
  2. Build in blender or food processor: add cilantro, jalapeño (or aji amarillo paste), and garlic.
  3. Add mayonnaise, Greek yogurt, lime juice, olive oil, and grated cheese to the blender or processor.
  4. Pulse to break down herbs, then blend on medium until mostly smooth, scraping down sides once or twice. If using an immersion blender, combine in a tall cup and blend until emulsified.
  5. Adjust texture: if sauce is too thick, add 1 tablespoon cold water at a time until desired consistency is reached.
  6. Season and finish: taste and add salt, pepper, or extra lime as needed. If too bitter, a pinch of sugar or extra cheese can balance the flavors.
  7. Chill (optional): refrigerate 15–30 minutes for best flavor meld. Sauce will thicken slightly as it chills.
  8. Store: transfer to an airtight jar and refrigerate up to 5–7 days. Stir before using.