Preheat the oven to 350 degrees F.

Heat a large (12-inch), nonstick skillet with an ovenproof handle over medium-high heat.

Add olive oil to the hot pan and sauté sliced onions for 3 minutes, until softened.

Add minced garlic and crumbled meatballs to the skillet and cook for an additional 2 minutes.

Melt butter in the same skillet and add cooked spaghetti.

Toss the spaghetti to coat it well with the butter.

In a separate bowl, whisk together eggs and heavy cream until slightly foamy.

Season the egg mixture with salt and pepper.

Pour the egg mixture into the skillet over the spaghetti and meatballs.

Stir gently until the eggs start to thicken, about 1 1/2 to 2 minutes.

Stop stirring and let the eggs set on the bottom for about 1 minute.

Sprinkle grated Parmesan cheese over the top of the frittata.

Transfer the skillet to the preheated oven and bake for 12 to 15 minutes, or until the frittata is set and golden brown.

Remove the frittata from the oven and place it on a plate.

Garnish with fresh chopped parsley.

Serve immediately with warmed, leftover spaghetti and meatballs sauce.

To prepare the sauce, heat bacon drippings (or olive oil) in a Dutch oven over medium-high heat.

Add diced onions and cook until softened and translucent, about 8 minutes.

Add chopped garlic and crushed red pepper flakes, stirring for 1 minute.

Add crushed tomatoes, tomato sauce, and tomato paste to the Dutch oven.

Season the sauce with dried basil leaves, dried oregano leaves, salt, and pepper.

Bring the sauce to a simmer over medium-high heat, stirring occasionally.

In a large mixing bowl, combine ground chuck, ground pork sausage, red wine, a lightly beaten large egg, minced green onions, minced garlic, chopped fresh parsley leaves, grated Parmesan, kosher salt, pepper, and Essence.

Mix together until just combined.

Form meatballs by rolling the meat mixture into 1 tablespoon-sized balls.

Place the meatballs on a plate as they are formed.

Gently place the meatballs into the simmering sauce, one at a time.

Allow the sauce to return to a simmer and cook, partially covered.

Let the meatballs rest undisturbed for 25 minutes before stirring.

When the meatballs rise to the top, stir gently.

Simmer, partially covered, for an additional hour, stirring occasionally to prevent sticking.

Remove the sauce from the heat and serve over cooked spaghetti.

Reserve leftover sauce and meatballs for the Pasta Frittata.