Make the béchamel sauce by first melting the butter over LOW heat and stirring in the oil once butter has melted. Gradually whisk in the flour until you have developed a golden paste.
Slowly add the milk, bit by bit, stirring constantly. Use an immersion blender to completely blend smoothly.
Add the chicken broth and stir so that it is all evenly distributed.
Turn the heat up to medium. Keep stirring and once the mixture bubbles, turn the heat back down to low.
Add 1/2 tsp of salt, pepper to taste, and 1/4 cup of the shredded romano cheese. Remove the sauce from heat.
Preheat oven to 350 degrees.
In a large bowl, toss the cooked pasta with olive oil, a dash of salt and pepper, 1/4 cup of romano cheese, and 1/4 cup of shredded mozzarella. Add about 2 tbsp of the béchamel to the pasta and toss until the penne is all well coated in flavor.
Layer the casserole in a 9 inch rectangular dish in even layers in the following order: half of the pasta, all of the beef, the other half of the pasta, then the béchamel sauce. Bake at 350 degrees for about 30 minutes, uncovered. Set to broil for the final 3-5 minutes to achieve a golden color on top.
Allow the casserole to cool for about 10 minutes before slicing and serving. Bil hana will shifaa!