Preheat the oven to 375° F.
Prepare a baking sheet with parchment paper and set aside.
Clean and slice the onion, optional.
Add oil to a small skillet, toss in the sliced onion and saute at a medium high heat until slightly browned, remove from the heat, set aside.
Butter the sliced bread on both sides and lay on the parchment lined baking sheet.
Slice the cheese and place onto a slice of buttered bread.
If adding the sauteed onion, add on top of the cheese.
Clean and thinly slice the pear, lay on top of the onions.
Butter the top slice of bread on both sides and lay on top of the finished sandwich.
Place the filled baking sheet into the oven and bake for 10 minutes.
Remove the baking sheet after 10 minutes and flip the sandwiches.
Return to the oven for about another 5 minutes.
After the cheese has melted and the bread is browned, remove from the oven.
Serve these Baked Cheddar Pear Sandwiches with a side of honey mustard or the maple mustard or if you can open the sandwich, drizzle on top.