Preheat oven to 425F and line a large baking sheet with parchment paper.
In a blender or food processor, combine all pesto ingredients and pulse until chunky smooth. Add salt as needed. Keep stored in the fridge for up to 2 weeks, if not using all.
In a large bowl, add your sliced zucchini, portabellas and onions. Add your olive oil, balsamic glaze, fresh thyme, smoked paprika, garlic powder, salt and red pepper and toss to coat your veggies. Let sit 5 minutes.
Lay your veggies flat on baking sheet and bake for 8-10 minutes.
While veggies are baking, slightly toast up your bread on a cast iron. Then slather both sides with tarragon pesto.
Remove veggies from oven and cool slightly.
Begin layering your sandwich, working with the bottom piece of bread, layer with sliced roasted red peppers, artichoke hearts and roasted veggies.
Then top with burrata, arugula and hemp seeds. Drizzle with a little olive oil, balsamic glaze and flaked salt and add top half of bread and gently push down.
Slice sandwich and serve warm or wrap in plastic wrap and keep in fridge for 1 day.