Prep. Slice the avocado in half, remove the seed and discard, using a tablespoon scoop out the avocado and put it into a bowl. Add 1/2 tablespoon of extra virgin olive oil, diced red onions, and salt and pepper to taste. Place the avocado mixture in the refrigerator until you need it.
In a large skillet add one tablespoon of olive oil and one tablespoon of unsalted, when the oil is hot cook salmon fillet or steaks for 2 to 4 minutes, thinner cuts 2 minutes and thicker slices 4 minutes. Season with salt and pepper to taste. Transfer cooked salmon to a warm plate to rest.
In a small non-stick skillet, over med-high heat, add a single (1) tablespoon of EVOO and a single (1) tablespoon of unsalted butter when the oil and butter mixture is hot add the chopped Brussels sprouts. Sauté for 4 -5 minutes, Brussel sprouts should be bright green and tender, transfer the sprouts to a bowl and set aside.
Whip the skillet clean and add one tablespoon of EVOO and one tablespoon of sweet cream butter. When the oil/butter mixture is hot toast sliced bread on both sides. And transfer the toasted bread to a dinner plate.
Add sautéed Brussels sprouts to one toasted slice of bread, on the other toasted slice of bread slather on the avocado spread and top with pan-fried salmon.