In a small skillet, toast the fennel seeds over medium heat for 1-2 minutes until fragrant. Remove from heat and let them cool for a few minutes.
Once the fennel seeds have cooled, grind them using a mortar and pestle or a spice grinder until they are roughly crushed.
In a large bowl, combine the ground pork, crushed fennel seeds, paprika, dried oregano, red pepper flakes, garlic powder, salt, and black pepper. Mix well until all the ingredients are evenly incorporated.
Using your hands, shape the mixture into sausage links or patties according to your preference. If making links, twist and secure the ends with kitchen twine.
Heat the olive oil in a large skillet or grill pan over medium heat.
Cook the sausages in the preheated pan for about 4-5 minutes per side or until they are cooked through and browned.
Once cooked, remove the sausages from the pan and let them rest for a few minutes.
Serve the homemade hot Italian sausages hot with your favorite accompaniments, such as crusty bread, grilled vegetables, or pasta.