Rinse the fresh spinach under cold water. Drain well and set aside.
In a large pot, bring water to a boil. Add the spinach and blanch for about 2-3 minutes until wilted and vibrant green.
Remove the spinach with a strainer and immediately transfer it to a bowl of ice water to stop the cooking process. After a few minutes, drain again and gently squeeze out excess water.
Divide the blanched spinach into two equal portions for each salad variation.
For the Basic Spinach Salad: In a mixing bowl, combine sesame oil, soy sauce, minced garlic, and salt to taste. Add the blanched spinach and toss gently until well coated. Transfer to a serving dish and sprinkle with sesame seeds.
For the Spicy Spinach Salad: In another mixing bowl, combine sesame oil, soy sauce, minced garlic, gochugaru, rice vinegar, and salt to taste. Toss the second portion of blanched spinach in this mixture. Transfer to a serving dish and sprinkle with toasted sesame seeds.
Serve both salads chilled or at room temperature. Enjoy them together or separately!