In a cold cast iron pan, render down the bacon. Once the pieces are crispy, remove from the pan and place in a small food processor.
Add 1 tablespoon of fresh chopped oregano and the minced garlic to the food processor.
Clean and slice the leek, cutting into small pieces. Cut the cherry tomatoes into small pieces.
Add the leeks and cherry tomatoes.
Turn the heat down to medium on the pan and add the leeks and tomatoes to the bacon fat. Saute for a couple minutes until the leeks have softened.
Once softened, add to the food processor.
Set the pan aside for frying the fish in.
Start the oven preheating to 450°F.
Let cool for 20 to 30 minutes then whiz briefly to combine.
Give the 2 pieces of fillet a sprinkling of salt and pepper on both sides.
Place a layer of stuffing on one side of each piece of basa, pressing down lightly.
Starting from the tail end, gently roll into a cinnamon bun shape, using toothpicks to pin closed.
Melt the butter in the pan and add a drizzle of the avocado oil.
Gently place the rolls (edge side down) in the pan and let brown. Tilt the pan a bit and use a spoon to scoop butter over the fish, basting it.
Gently flip over to the other edged side and brown. Tilt the pan a bit and use a spoon to scoop butter over the fish, basting it.
Brown the outside of the fish (for a minute with each rotation of the roll.) Just be gentle so that the stuffing doesn't start falling out of the cut ends.
Set the fish back onto a cut end.
Pop the pan into the oven and bake for 5 minutes.
Don't forget to take out the toothpicks before serving!