1. Preheat oven to 350 degrees.
2. Cook pasta "al dente" and have it timed so it is still hot when adding bechamel (cheese) sauce
For Beachamel Sauce
3.Stud the peeled onion with 4 cloves. In a medium sized saucepan, add 2 cups of milk, the studded onion and bay leaf. Bring to a low simmer while stirring occasionally for about 15 minutes.
4.Remove the studded onion and bay leaf after the 15 minutes and set the hot milk aside.
5.Making a Roux: In a large pot, melt the 3 tbsp of butter over medium heat then slowly stir in the ¼ cup of flour with a small whisk. Reduce the heat to a low setting. The mixture should thicken quickly but continue to stir for about 2 minutes. It should develop a pale tan color.Over low heat, slowly add the hot milk to the roux while whisking. Once all of the milk is added and the béchamel is smooth, take it off the heat and add the cheese, salt, pepper, thyme and both Dijons (use more or less Dijon according to taste - if you love mustard as much as we do, add double the amount listed above).
6. Add the cooked pasta and lobster and mix slowly.
For Panko Crumb Topping
7. Melt 2 tbsp of butter in a small pan over low heat and add the ¼ cup of panko. Stir until butter is absorbed.
8.Have 4 individual-sized baking dishes ready and place them on a baking sheet. Divide the mixture between them. Sprinkle the panko crumbs on top and bake for about 20-30 minutes until tops start to brown and sauce bubbles. Do not cook longer than this as the lobster will overcook and become chewy.
9. Serve still hot from the oven and feel free to add some fresh thyme as garnish.