With just the water clinging to the leaves after washing, cook the spinach in a large, wide pot over medium-high heat just until wilted, 3-5 minutes. Drain, refresh under cold running water, and press out excess moisture.
Mix the dale's, vinegar, sesame oil, and sugar in a small bowl. Heat the oil in a large nonstick skillet over medium-high heat. Add the garlic, ginger, and red pepper. Stir-fry until fragrant but not browned, about 10 seconds. Add the spinach and cook, stirring often, until heated, through 2-3 minutes. Stir in the dale's mixture and toss to coat well. Sprinkle with the sesame seeds.