For the Grilled Trout and Glaze

• 4 tbsp. unsalted butter
• 1 small bulb fennel, trimmed and thinly sliced
• ¹⁄₂ small yellow onion, thinly sliced
• 3 plum tomatoes, cored and quartered
• 3 sprigs thyme
• 1 lemon, zested and quartered, plus the zest of 2 lemons
• 4 cups chicken stock
• 2 (1-lb.) whole trout, cleaned and scaled
• 2 tbsp. olive oil
• Kosher salt and freshly ground black pepper, to taste

For the Carrot Purée and Spätzel

• 2 tbsp. unsalted butter
• 1 ¹⁄₄ cups carrot juice
• 1 ¹⁄₂ tbsp. white wine vinegar
• 2 medium carrots, thinly sliced
• 2 cups flour
• ¹⁄₂ cup crème fraîche
• ¹⁄₂ cup milk
• 1 tbsp. finely chopped thyme
• 1 ¹⁄₄ tsp. Dijon mustard
• 3 eggs
• Zest and juice of 1 lemon
• ¹⁄₄ cup olive oil
• 2 oz. baby spinach
• Kosher salt and freshly ground black pepper, to taste

Instructions

1. Make the glaze: Melt 2 tbsp. butter in a 4-qt. saucepan over medium-high heat. Add fennel and onion; cook until soft, 10–12 minutes. Add tomatoes, thyme, and quartered lemon; cook until tomatoes are broken down, 8–10 minutes. Add stock; boil. Reduce heat to medium-low; cook until liquid is reduced by half, about 30 minutes. Strain liquid, discarding vegetables, and return to saucepan; bring to a simmer. Cook until reduced by half again, 15–20 minutes. Remove glaze from heat; stir in 2 tbsp. butter, plus the zest from one lemon, salt, and pepper.
2. Make the purée: Boil 2 tbsp. butter with carrot juice, vinegar, carrots, salt, pepper, and 1 cup water in a 2-qt. saucepan until carrots are very tender, about 20 minutes; purée until smooth in a blender. Keep both glaze and purée warm.
3. Make the spätzle: Bring a large pot of salted water to a boil. Whisk flour, crème fraîche, milk, thyme, mustard, eggs, and half the zest with salt and pepper in a bowl into a smooth batter. Place a colander with large holes over the boiling water and working in batches, use a rubber spatula to press batter through holes into water. Cook until spätzle float, 2–3 minutes. Transfer spätzle to a colander. Heat oil in a 12" skillet over medium-high heat. Add spätzle, salt, and pepper; cook until golden, 8-10 minutes. Stir in spinach, remaining zest, and the juice.
4. Grill the trout: Heat a charcoal grill or set a gas grill to high. (Alternatively, heat a cast-iron grill pan over medium-high heat.) Brush trout with oil and season inside of each with the zest of one lemon, salt, and pepper. Grill, flipping once, until slightly charred and cooked, 15–18 minutes.
5. To serve, spread carrot purée on the bottom of 2 plates, top each plate with spätzle and a trout; brush trout generously with glaze.