Combine sage, crushed fennel seeds, garlic powder, onion powder, black pepper, red pepper flakes, salt, brown sugar, and thyme in a small bowl. Crushing the fennel seeds releases their aromatic oils, which infuses the sausage with that distinctive breakfast sausage flavor.

Add the ground pork to a large mixing bowl and sprinkle the spice mixture evenly over the surface. Using clean hands, gently mix the ingredients together until just combined. Avoid overmixing as this can make the sausage dense and tough.

Divide the seasoned pork mixture into 8 equal portions, roughly ¼ cup each. Roll each portion into a ball, then gently flatten into patties about ½-inch thick.

Heat a large skillet over medium heat—no oil needed since the pork fat will render out. Place the patties in the skillet, leaving space between each one. Cook for 4-5 minutes on the first side until golden brown and easily release from the pan.

Carefully flip each patty using a spatula. Cook for another 3-4 minutes until the internal temperature reaches 160°F. The sausages will feel firm to the touch and the juices will run clear.

Transfer the cooked sausage patties to a plate lined with paper towels to absorb excess grease. Let them rest for 2-3 minutes before serving to allow the juices to redistribute.