Heat oil in a large pan over medium-high heat. Chop the garlic clove and add to the pan, sautéing for 1-2 minutes until fragrant. Add the seasoned pork and sear for 3-4 minutes until browned. Chop the onions and add to the pan, cooking for 5 minutes, stirring occasionally, until translucent. Ensure the pork reaches 63°C (145°F) internally. Remove the pan from heat.
In a baking dish, layer the drained pasta, a layer of grated cheese, the meat and onion mixture, and the remaining grated cheese. Pour the hollandaise sauce evenly over everything.
Bake in a preheated oven at 210°C (410°F) for about 20 minutes until the cheese is melted and lightly browned.