Bring a medium pot of water to boil. First put in the kale, after two minutes add the frozen peas and cook for seven minutes. Two minutes before time is up add the broccoli florets. Drain and set aside to cool off a bit before you transfer it to a food processor.
In the meantime, heat some olive oil in a small pan and sauté the onion for 2-3 minutes. Then add the minced garlic and cook for another minute.
Place the cooked vegetables together with the chopped celery into a food processor and process for a couple of seconds. Make sure to leave some texture. Place in a medium bowl and stir in the oats, breadcrumbs, walnuts, and sautéed onion and garlic. Season with the Italian spice mix, soy sauce, mustard, salt, and black pepper.
Form four burger patties and set aside.
Then make the sun-dried tomato mayonnaise: Cut the sun-dried tomatoes into small pieces and stir in the vegan mayonnaise.
Cut the eggplant and red bell pepper into thin slices. Heat some olive oil in a griddle pan and roast them gently for 3-4 minutes until they are lightly brown.
In a large pan, heat some oil and cook the green monster veggie patties for 2-3 minutes on each side. Serve them on a burger bun with lettuce, the grilled veggies, and the sun-dried tomato mayonnaise.