Whisk dressing ingredients to blend. Season with pepper. Set aside. Can be made ahead. Heat butter over medium heat. Break noodles in small pieces and brown along with sesame seeds and almonds. Cool and drain on paper towels. Set aside. Can make ahead. Store in airtight container.
When ready to serve - add spinach, green onions, noodles, nuts and sesame seeds to same bowl. Toss with enough dressing to coat.