Place the vegetable oil, olive oil, and egg in a tall, narrow jar that fits the immersion blender to the bottom. Blend the oils and egg until thick and creamy, about 10 seconds.
Add the roasted and fresh garlic, lemon juice, vinegar, and salt to the aioli. Blend until the garlic is completely pulverized and the mixture is smooth and creamy.
Add the Sriracha to the jar and stir to combine. Store the aioli in a clean jar with a tight-fitting lid in the fridge for up to one week.
Notes
Using both roasted and raw garlic is key! Roasting garlic is super simple—don't skip it if you can help it.
I find 1 tablespoon of Sriracha has the perfect amount of heat for my taste and is a terrific balance between garlic and spice. If you prefer a little less, or a little more heat, add the Sriracha by the teaspoon. Stir it in well between each addition until you're happy with the heat level.