Preheat your oven to 350 degrees F. And prepare a baking dish.
Cook the pasta according to the packet instructions. Drain and set aside.
In a large skillet, heat the olive oil over medium-high heat. Add the minced beef and brown for 4-5 minutes until cooked. Reduce the heat and add the minced garlic. Cook for 1 minute then add the remaining meat sauce ingredients. Simmer the sauce for 30 minutes until thick.
For the white sauce, melt the butter in a large saucepan over medium heat. Add the flour and stir for 1 minute. Slowly pour in the milk, while stirring constantly. Simmer the white sauce for 5 minutes on low heat until thick enough to coat the back of a wooden spoon... but not so thick you could cut it with a knife!
Remove the white sauce from the heat and add the parmesan cheese. I mean, who doesn't love a little Parmesan on everything? It's really the glitter of the food world. Season with a pinch of salt.
Place the cooked pasta in the prepared baking dish and arrange them so they are going in the same direction. Top the pasta with the meat sauce then pour over the white sauce. Sprinkle with the feta cheese and bake for 30 minutes until the cheese turns golden.
Cool the pasta for 10 minutes before slicing it. Garnish with fresh thyme leaves and enjoy!