Cook pasta according to al dente, drain, then set aside to cool.
In saucepan, melt Kerrygold Unsalted Butter over medium heat, add onion and lightly season with salt, cook onion until translucent.
Add flour and cook 2 to 3 minutes, stirring constantly. Whisk in milk and cream and incorporate totally. Bring mixture to a simmer; add bay leaf.
Reduce burner to low heat. Cook for 10 to 15 minutes, stirring occasionally. Turn off heat and remove bay leaf.
Whisk in 1 cup each of the Kerrygold Cheddar and Swiss Cheeses, until incorporated. Season with salt, pepper.
Incorporate lobster into the pasta and cheese. Spoon into 2 1/2-quart casserole dish, cast iron skillet or individual dishes.
Top with grated Dubliner® Cheese, thyme, and a small handful of breadcrumbs.
Bake at 375° F for 8 to 10 minutes until it is golden brown on top.