Ingredients
2 medium zucchini (each 9 ounces), coarsely grated
Kosher salt and freshly ground pepper
1 tablespoon extra-virgin olive oil
1 clove garlic, smashed
10 ounces baby spinach
1/2 cup unbleached all-purpose flour
1 teaspoon baking powder
2 large eggs, lightly beaten
1/2 cup finely grated Gruyere
2 scallions, trimmed and thinly sliced (1/4 cup)
2 tablespoons chopped fresh dill, plus sprigs for serving
Vegetable-oil cooking spray
1/4 cup creme fraiche or sour cream
4 ounces thinly sliced smoked salmon
Preparation
Sprinkle zucchini with 1 teaspoon salt; toss to coat. Transfer to a colander and let stand 10 minutes. Meanwhile, heat oil and garlic in a medium skillet over medium-high until garlic begins to sizzle. Add spinach and cook, tossing, until wilted, 2 to 3 minutes. Season with salt and pepper.
Preheat a waffle iron to medium. In a large bowl, whisk together flour and baking powder. Squeeze zucchini dry in a large potato ricer or a clean kitchen towel; transfer to a bowl. Stir in eggs, cheese, scallions, and dill. Pour over flour mixture and gently stir to combine. (Batter will be very thick.)
Spray waffle iron with cooking spray. Spoon one-quarter of batter (about 1/2 cup) into center; spread into a 5-inch circle and close. Cook until golden brown and crisp, 7 to 9 minutes. Transfer directly to the rack of a 200-degree oven to keep warm while cooking remaining waffles. Serve warm, with spinach, creme fraiche, and salmon, sprinkled with dill sprigs and pepper.