Preheat oven to 400°F and line baking sheet with parchment paper.

Cut squash in half lengthwise, remove seeds, and then pierce inside of squash with fork and brush with oil. Place on baking sheet cut side up and cook for 35–40 minutes. Remove and cool, then dig out spaghetti squash with a fork, creating pasta-like strands.

Slice steak into thin slices; cut each slice into matchsticks.

Heat a large wok or skillet over medium-high heat. Swirl in oil, then add scallions, garlic, ginger, and salt; cook, stirring, until fragrant, about 30 seconds. Add steak; cook for 1–2 minutes, continually stirring until just cooked through. Add squash strands and cook, stirring, for 1 minute. Add soy sauce, rice vinegar, Hoisin, and chile sauce; cook, continually stirring, until aromatic, for about 30 seconds. Remove from heat and season to taste with shichimi togarashi and hot sauce.

Garnish with bean sprouts, microgreens, or radishes.