To prepare the meat filling: heat 2 tbsp of the olive oil in a stockpot or dutch oven over high heat. Add the beef, Middle Eastern Spice Blend, red pepper flakes, salt and pepper and cook, breaking up the meat, until browned, about 10 minutes.
Drain the fat from the meat by pouring into a large colander that's been placed in the kitchen sink.
Return the pan to the heat and add the remaining olive oil. Heat over high heat.
Add the onions, red bell pepper, and garlic and cook until soft, about 6 minutes.
Add the tomato paste, oregano, thyme and bay leaf and cook for 2 minutes. Return the beef to the pan.
Add the wine to the pan, and cook, until almost evaporated, about 6 minutes.
Add the crushed tomatoes and bring to a boil. Reduce the heat to med-low and simmer, uncovered, until thickened, about 45 minutes. Stir in the parsley and adjust the seasoning with salt and pepper, if needed.
Remove from the heat and set aside.
To prepare the bechamel: melt the butter in a medium saucepan over medium heat.
Add the flour, whisking constantly and cook for 1 minute, or until you can no longer smell the flour. While whisking constantly, add the milk and bay leaf and cook until thickened. Your whisk should leave marks or streaks when pulled through the sauce.
Season with salt, pepper, and nutmeg and discard the bay leaf.
Let the sauce cool for 5 minutes.
In a small bowl, whisk together the egg yolks and whisk into the bechamel sauce until smooth.
Whisk in the finely crumbled feta cheese, and lemon zest. Set aside, stirring occasionally while you fry the eggplant.
Preheat the oven to 400 degrees F. Lightly grease a 9x13" baking dish or casserole dish.
To fry the eggplant: Season the eggplant slices on both sides with salt and pepper.
Heat about 2 tbsp of canola oil in a large skillet over med-high heat.
Working in batches, fry the eggplant slices until lightly golden brown on both sides, about 5 minutes. Transfer the eggplant slices to paper towels, making sure to blot to remove excess oil.
Continue to fry the eggplant slices, adding oil conservatively to the pan, if needed.
Assembling the moussaka: put half the eggplant slices in the dish and cover with half the meat sauce.
Top the sauce with the remaining eggplant slices followed by the remaining meat sauce.
Pour the bechamel over the surface and spread evenly with a spoon or metal icing spatula.
Place the dish on a baking sheet, or piece of aluminum foil (it likes to bubble over) and bake until lightly browned and bubbly, 40-45 minutes.
Garnish the top with parsley.
Let cool for at least 30 minutes before cutting and serving.