Preheat the oven to 425 degrees.
On a parchment lined baking sheet, toss the vegetables with the olive oil, honey, ½ teaspoon of salt and the za’atar. Roast in the oven until tender and caramelized, 25-30 minutes.
Remove the vegetables to a bowl and arrange the bread on the baking sheet. Toast in the oven until golden brown, about 3 minutes per side.
Arrange the toast on a work surface. When cool enough to touch, top each with ½ an avocado and press into the bread with a fork until you have an even layer. Alternatively, you can mash the avocado in a bowl and then spread it on the bread. Season the toast with the remaining salt.
Divide the roasted vegetables between the slices of bread and drizzle with the yogurt tahini sauce. Garnish with hemp seeds, if using, cut in half and enjoy immediately as an appetizer or meatless lunch.