Preheat your oven to 400°F and line a baking sheet with parchment paper for easy cleanup.
In a medium mixing bowl, combine the lean ground beef, egg, minced garlic, dried oregano, sea salt, black pepper, and grated parmesan cheese.
Gently mix the ingredients by hand until just combined, being careful not to overwork the meat which ensures a tender texture.
Roll the mixture into small, uniform meatballs and place them on the prepared baking sheet.
Bake the meatballs for 12-15 minutes until they are cooked through and have a light golden exterior.
While the meatballs roast, bring a large pot of filtered water to a rolling boil and cook the sourdough spaghetti until al dente.
In a small saucepan, gently warm the marinara sauce over medium-low heat until it begins to simmer.
Drain the cooked spaghetti and immediately toss it with the warm marinara sauce to coat every strand.
Plate the pasta and top with the hot meatballs, finishing with an extra sprinkle of herbs if desired.