Kosher salt and freshly ground black pepper (optional)
MAKE THE SAUSAGE PATTIES:
In a large bowl, mix the pork, onion, brown sugar, garlic, vegetable oil, sage, red pepper flakes, salt, and pepper with your hands until uniform (don’t, like, mash it or overmix it – just until it’s all nicely mixed together). Form into four 4-inch round patties.
Coat a cast iron skillet with oil and heat over medium-high heat. Add the sausage patties and fry until browned and cooked through, about 4 minutes per side (8 minutes total).
Transfer to a platter and cover to keep warm.
ASSEMBLE THE SANDWICHES:
Split and toast the English muffins, then butter them. Season with a pinch of salt and pepper if you’d like.
Arrange 1 thick or 2 regular slices of cheese on 4 of the muffin halves. Top each with a sausage patty and an egg.
Squirt some Sriracha on top of the eggs and top with remaining muffin halves.