Preheat the oven to 350 degrees and grease a large casserole dish.

Cook pasta one minute short of package instructions. It will continue to cook in the pasta bake so you want it under cooked.

Two minutes before pasta is scheduled to finish cooking, add the spinach to the pasta water to wilt. Cook along with pasta. Drain the pasta and spinach.

Meanwhile, in a large pot, saute the onion in the olive oil over medium heat. Season with ¼ teaspoon of the salt and pepper. Cook until starting to brown.

Add the flour and garlic. Stir and coat the onion evenly with the flour. Cook for one minute.

Gradually add the broth and milk stirring frequently. Allow the sauce to come to a low boil to thicken. Stir for several minutes or until thick.

Remove from the heat and stir in 1 cup of the cheese. Season with nutmeg. Add the rest of the salt and pepper to taste.

Stir in the pasta, spinach and add the lemon juice. MIx well.

Put in a ** casserole dish and sprinkle the panko and remaining ¼ cup of cheese on the top.

Bake for 20 minutes or until the top is bubbly and brown.