1
In a small saucepan, heat the water, sugar, vinegar, and salt. Place the onions in a heatproof bowl, cover with the vinegar mixture and cool to room temperature.
2
To make the aioli, combine all the ingredients in a small bowl. Stir well with a whisk.
3
To make the vinaigrette, combine all the ingredients other than the oil and fresh herbs in a blender or food processor. Purée until smooth. With the motor running, drizzle in the oil until emulsified. Fold in the herbs and season with salt and pepper.
4
Form the burger into 4 patties. Sprinkle with salt and pepper.
5
Heat the canola oil in a medium skillet over medium-high heat. Cook the patties for 4 minutes per side or until lightly browned and cooked through. Add a slice of cheese to each burger after flipping.
6
Toss the mixed greens with the harissa vinaigrette in a large bowl.
7
Serve the burgers on hamburger buns, topped with aioli and pickled onions, alongside salad.