Preheat the oven to 400 degrees F. Mix the soy sauce, maple syrup, orange juice, 2 garlic cloves and 2 tablespoons water in a large bowl; add the salmon and turn to coat. Cover and refrigerate 20 minutes.
Meanwhile, put the cauliflower and broth in a microwave-safe bowl; cover loosely with plastic wrap and microwave until tender, 6 minutes.
Coat a rimmed baking sheet with cooking spray. Drain the fish, season with salt and pepper and place on the prepared baking sheet. Bake until slightly golden around the edges, 8 to 10 minutes.
Meanwhile, heat the olive oil and remaining garlic clove in a large skillet over medium-high heat; cook, breaking up the garlic with a spoon, until softened, about 2 minutes. Add the cauliflower and broth, the cranberries, pistachios, orange zest, parsley, 1/4 teaspoon salt, and pepper to taste and stir to heat through. Serve with the fish.
Recipe courtesy Food Network Magazine