For the rice vinaigrette: Whisk together 1/4 cup pickling liquid from quick pickles, 1 Tbsp. avocado oil, 1 Tbsp. toasted sesame oil, and 1/4 tsp. kosher salt. Cover; keep at room temperature.
For the asparagus: Sauté 8 oz. asparagus in 2 tsp. grapeseed oil until tender. Chop; toss with 1/2 tsp. toasted sesame oil.
For the mushrooms: Sauté 8 oz. trimmed, chopped oyster mushrooms with 1/2 tsp. grated fresh garlic and 1/2 tsp. minced fresh ginger in 1 Tbsp. grapeseed oil until tender. Toss with 1 tsp. toasted sesame oil.
Combine spinach, salmon, asparagus, mushrooms, and carrot in a bowl; drizzle with vinaigrette. Sprinkle with salt and sesame seeds, if desired.