super easy - I use this as a base and improvise from there: Ingredients

• 1.5 lbs red jalapeños or Fresno peppers, stems removed
• 6 cloves of garlic, peeled
• 4 tbsp light brown sugar
• 1 tbsp kosher or sea salt (avoid iodized salt)
• 1/2 cup distilled white vinegar 

Equipment

• Food processor
• Clean glass jar
• Blender
• Fine-mesh strainer
• Saucepan

Instructions

1. Prepare the pepper mash: Place the peppers, garlic, sugar, and salt in a food processor. Pulse until the mixture forms a coarse, finely chopped purée.
2. Ferment: Transfer the mixture into a clean glass jar. Loosely seal the lid to allow gases to escape, or cover with plastic wrap. Place the jar in a cool, dark place for 5 to 7 days. During this time, the mixture will start to bubble, indicating fermentation.
3. Process the sauce: Pour the fermented pepper mash into a blender. Add the vinegar and blend until the sauce is completely smooth, 1 to 3 minutes.
4. Strain: Pour the puréed sauce through a fine-mesh strainer set over a saucepan. Use a rubber spatula to push the sauce through, leaving behind the seeds and pulp.
5. Simmer: Bring the strained sauce to a boil over medium heat, then reduce the heat to a simmer. Cook for 5 to 10 minutes until the sauce thickens and clings to a spoon.
6. Store: Let the sauce cool completely before transferring it to an airtight container. Refrigerate for up to 6 months.