Dice the granny smith apple after peeling and coring.

Toss the diced apple with lemon juice to prevent browning.

Set the apple mixture aside.

In a medium, wide, heavy saucepan, combine brown sugar, minced onion, red wine vinegar, finely minced garlic, and cassis over medium heat.

Bring the mixture to a boil, then reduce heat to low and simmer for 5 minutes, stirring occasionally.

Add the apple and lemon juice mixture to the saucepan and simmer for 10 minutes, stirring occasionally.

Incorporate the blackberries, freshly grated ginger, and lemon zest into the saucepan.

Continue to simmer for an additional 10 to 15 minutes, stirring occasionally, until the chutney has slightly thickened.

Remove the saucepan from the heat.

Transfer the chutney to a bowl and allow it to cool completely before serving.