Divide the breakfast sausage into two even patties (about ⅓ lb each).
Dice the onion if you haven’t already.
Preheat the griddle to 375–400°F. Add a little avocado oil and spread it around, then drop on the butter.
Toss the hash browns into the oil and butter. Season with salt and pepper, then divide into two piles. Spread them thin and let them cook undisturbed for about 10 minutes.
Add the diced onions to the griddle.
Place the sausage patties on the griddle and cook for about 5 minutes per side, or until fully cooked through.
Once the patties and onions are done, move them to a cooler corner of the griddle to stay warm.
Add a small amount of oil, then crack the eggs directly onto the griddle. Pop the yolks if you want them fried. Cook about 2 minutes per side.
Toast the Texas toast slices on the griddle until golden brown.
Flip the hash browns once they’re crispy and golden on the bottom. Top each pile with a slice of American cheese, then a scoop of grilled onions.
Build your sandwich: toast, Sriracha mayo, lettuce, tomato, smothered hash browns, sausage patty, egg, then the top piece of toast.