Preheat the oven to 350°F (180°C).
Remove the tomatoes from the vines and cut in half or quarters and place on a baking sheet. Sprinkle the tomatoes with salt and pepper and a drizzle of olive oil (optional) and bake in the oven for 35 minutes until soft.
While the tomatoes are baking, prepare the barley by placing it in a sieve and rinsing it under cold running water. Place the barley into a saucepan and cover with water until 1-inch (5cm) above the barley. Bring to the boil then reduce the heat to low and allow to simmer uncovered for 35 minutes.
Drain the chickpeas and place them on a baking tray. Toss them with sriracha sauce and a sprinkle of salt and pepper. Place the tray into the oven and bake the chickpeas for the last 10 minutes of the tomato cooking time.
Sauté the onion, crushed garlic, and thyme in a large soup pan. Add in 1 tablespoon of avocado oil (you can also substitute it with 1 tablespoon of vegetable stock), and sauté until the onions become translucent. Pour in ¼ of the whole roasted tomatoes and stir well.
Place the remaining tomatoes into a blender and blitz to smooth and pour into the soup. Add in the drained barley, chopped parsley, vegetable stock, coconut sugar and season with salt and black pepper to taste. Mix well to combine, bring to a boil and turn the heat down and allow to simmer gently for 10 minutes.
Serve the soup in bowls, topped with chickpea croutons.