Blueberry Oatmeal Pie

I just sorta came up with this out of the blue.  I really wanted to use oats in a dessert that wasn't cookies or the top of a crumble.

For the blueberry filling
200 gm frozen blueberries
1/3 cup brown sugar
1 tbsp balsamic vinegar
juice of 1/2 lemon
zest of 1 lemon
1/4 tsp cinnamon
1 tbsp cornstarch
1/4 tsp salt

For the oat custard
1 stick butter, at room temperature
1 cup sugar
3 eggs
30 grams rolled oats, toasted in a pan over medium heat until they smell nutty
1/4 cup half and half
1/4 tsp sesame oil
1/2 tsp cinnamon

frozen pie crust (I know it's cheating)

rolled oats and demerara sugar to sprinkle on top

1. Preheat oven to 350. Combine all the ingredients for the blueberry filling except the cornstarch in a small saucepan. Cook over medium low heat for about 15 minutes. Mix the cornstarch with 1 tbsp water to make a slurry, stir into the blueberry filling and continue to cook until thickened.
2. Run the toasted oats through a blender until until they are the consistency of flour.
3. Cream the butter, sesame oil and sugar together; beat the eggs in one at a time and then drizzle in the half and half. mix in the ground toasted oats and cinnamon
4. press the pie crust into a pie tin. Spoon in the blueberry mixture and then top with the oat custard.  Sprinkle the top with rolled oats and some demerara sugar.
5. Bake for about 50 minutes or until the top is brown and only slightly jiggles when shaken.  Let cool completely before slicing and serve with clotted cream.