Step 1

In a medium saucepan, bring the water to a boil over medium-high heat.

Step 2

Whisk in the chickpea flour and salt. Cook for 1 minute, whisking constantly. Reduce the heat to medium-low; cook, whisking, for 4 to 5 minutes longer, until thickened. Transfer mixture to glass bowl or container; cover and refrigerate until cold.

Step 3

Transfer the cold chickpea mixture to a blender. Add the oil, lemon juice, mustard, salt (as desired) and optional cayenne; blend for at least 3 to 4 minutes, stopping to scrape down sides of container, until the mayonnaise is blended, light, fluffy and pale in color.

Step 4

Store in the refrigerator for up to 2 to 3 weeks. Reblend, if needed, if any separation occurs. Use as you would any other mayonnaise or aioli!