1. Get a pot, put your sweet potatoes in it, and cover them with water. Bring the water to a boil and then reduce heat to the lowest simmering temperature to cook your potatoes. They're done when they're very tender, after about 12 to 15 minutes. Drain them when they're done.
2. Get out your food processor and throw in your sweet potatoes, cauliflower, sesame seeds, garlic, paprika, cumin, coriander, salt, and pepper. Puree until smooth. Add the egg and then pulse until it's mixed in. Finally, add your flour and bread crumbs and pulse until they're evenly mixed in.
3. Split your mixture into as many patties as you need for your burgers and shape them into round patties.
4. Put some olive oil in a pan over medium heat and cook your patties until they're golden brown on both sides, flipping once. They'll take about 4 minutes on each side.
5. In a bowl, whisk together your mayonnaise and hot sauce. In another bowl, mash up your avocado with some lemon juice.
6. To assemble your burgers, spread the spicy mayonnaise on the bottom bun, put a lettuce leaf on that, then your burger patty, then your avocado mixture, then the green onions, and finally the top bun. Repeat for the rest of your burgers.