Heat olive oil over medium-high heat in a large skillet. When oil is hot, add garlic, salt, and pepper and sauté until garlic is fragrant and cooked through, about 1 minute (careful not to burn it!)
Add fresh blackberries and blackberry jam to skillet and whisk until jam has broken down and formed a smooth sauce.
Whisk in red wine and bring to a simmer. Let the sauce cook for 3-4 minutes until it has thickened slightly.
Place salmon portions into the saucepan and spoon a few spoonfuls of sauce over the top of the fish. Continue cooking, spooning additional sauce over the fish every minute or so, until fish is flaky and cooked through (9-11 minutes, depending on how done you like your fish). The sauce should thicken considerably by this point, reducing to a nice glaze that you can spoon or brush over the fish just before serving.
Remove fish from pan and top with a spoonful of the glaze (or brush it on with a pastry or silicone brush) and a few berries from the saucepan. Sprinkle fresh parsley on top (optional) and serve immediately.
