In a small bowl, whisk together tahini, soy sauce, lemon juice, and 2 tablespoons water until thoroughly blended and creamy; set aside.
In a large pot of boiling salted water, cook dandelion greens until wilted, 2 to 4 minutes. Drain, spreading greens out in the colander to prevent further cooking.
Dry empty pot and return to stove. Add oil and garlic and cook over medium-low heat, stirring frequently, until garlic is golden, about 2 minutes. Stir in the dandelion greens; season with salt. Pour the tahini mixture over the greens and mix thoroughly until the sauce thickens and the flavors have mingled, about 2 minutes. Serve immediately.