In a small bowl, stir together 3 tbsp. EVOO and the garlic.
Position the oven rack 6 inches from the broiler and preheat. Arrange the asparagus in a single layer on a foil-lined rimmed baking sheet. Drizzle with 1 tbsp. EVOO and season with salt and pepper. Broil until crisp-tender, about 3 minutes. Transfer to a salad bowl.
Place the mushrooms on the same baking sheet. Brush all over with the garlic oil and season with salt and pepper. Broil gill side up for 7 minutes. Scatter the scallion whites on top, flip over the mushrooms and broil until cooked through and lightly browned, about 4 minutes. Transfer to a cutting board to cool slightly.
Meanwhile, in a bowl, whisk together the lemon juice, lemon zest and remaining 2 tbsp. EVOO. Chop the mushrooms into bite-size pieces and add to the asparagus, along with the scallion greens, spinach and frisee. Drizzle with the lemon dressing, season with salt and pepper and toss. Top with the gouda.