Add the chopped rhubarb, sugar, red wine vinegar, freshly grated ginger, bay leaf, cloves, 2 tablespoons water, and a pinch of salt and pepper to a small saucepan.
Heat the saucepan over a medium heat and allow the mixture to stew for 5 to 10 minutes, until the rhubarb is soft.
Stir the mixture well and set aside.
Line a baking dish with parchment paper.
Place the salmon fillets into the dish and top each with a chunk of butter and a pinch of salt and pepper.
Place the salmon fillets into the oven to bake for 10 to 12 minutes, until just cooked through.
Serve the salmon hot, topped off with a few spoonfuls of rhubarb sauce.