Tonnato Sauce with Grilled Vegetables

Combine the tuna, egg yolks, lemon juice, fish sauce, garlic, and salt in a blender on high to form a paste, stopping the blender and scraping down the sides if necessary, about 20 seconds. With the motor running, slowly drizzle in the canola oil until everything is emulsified, about 1 minute. Season with salt to taste. Chill until ready to use; sauce lasts up to 1 week stored in an airtight container in the fridge.

Heat a grill or grill pan over high heat. Toss the vegetables with the oil and salt in a bowl and grill, turning once, until charred but not mushy, 5 minutes.

Serve the vegetables warm or at room temperature with the tuna sauce.