Remove the tops from 15–16 red Fresno peppers. Slice peppers in half lengthwise. Remove seeds if you prefer a milder sauce, but leaving them adds heat.

In a bowl, dissolve 3½ tablespoons of kosher salt in 4½ cups of filtered water.

Place peppers in a clean half-gallon jar. Pour the saltwater brine over the peppers until fully submerged (use a small ramekin or weight to keep peppers below the brine). Seal the jar and let it ferment at room temperature for 5–12 days. Check daily; a cloudy brine is normal, but discard if mold or fuzz develops.

Heat ½ cup of canola oil in a small pot over low-medium heat. Add 5 peeled garlic cloves and toast until light golden brown, stirring frequently to avoid burning. Strain garlic from the oil, reserving both.

In a hot pan with a splash of olive oil, cook ½ stick diced celery and ½ shredded carrot with a pinch of kosher salt for about 3 minutes until softened.

Pour the jar contents through a strainer, reserving the brine separately. Transfer the fermented peppers to a blender.

Into the blender with the peppers, add: Toasted garlic cloves, ½ cup + 2 tablespoons white vinegar, 4 tablespoons reserved pepper brine, Sautéed carrot and celery, ½ of the reserved garlic oil, Blend until smooth and creamy.

Pour the blended sauce through a fine-mesh strainer or cheesecloth into a bottle or jar to achieve a silky texture.

Transfer the finished sauce into a clean, airtight bottle. Refrigerate for up to 4 weeks. Shake before each use.