1. For the salad: Bring a large pot of water to a boil over high heat. Prepare an ice-water bath and set aside. Add fava beans to boiling water and cook until crisp-tender; drain and transfer to ice-water bath to cool. Drain and transfer to a large bowl. Repeat process with fiddleheads and carrots. Repeat process with snap peas; when snap peas have cooled, trim ends and slice open. Transfer fiddleheads, carrots, and snap peas to bowl with fava beans. Add radishes and golden beets; set aside.

2. Prepare an ice-water bath. Place morels in a large bowl and add enough cold water to cover; stir and remove morels from water; repeat process, changing water, until water runs clean. Transfer morels to a medium nonreactive bowl. Place sherry-wine vinegar, 1/2 cup water, 1 teaspoon salt, pickling spice, and sugar in a medium saucepan and bring to a simmer over medium heat. Strain vinegar mixture over morels and set bowl in ice-water bath to cool. Remove from ice-water bath and cover until ready to use.

3. Prepare an ice-water bath. In a medium saucepan, toast coriander, bay leaves, and pepper over low heat. Add wine and cook until reduced by half. Add vegetable stock, olive oil, lemon juice, thyme, and asparagus; place a parchment paper round over asparagus to keep submerged. Bring to a simmer and cook until asparagus is tender, about 20 minutes. Remove from heat and place saucepan directly in ice-water bath; let asparagus cool in liquid. When asparagus has cooled, cut each into 4 equal pieces; return asparagus pieces to cooking liquid and set aside.

4. Make the zucchini marmalade: Place squash, sugar, and salt in a small saucepan over low heat; cook, stirring occasionally, about 30 minutes. Remove from heat and let cool.

5. Make the elderflower vinaigrette: In a small bowl, whisk together oil, vinegar, and elderflower cordial; season with salt and set aside.

6. To serve: Place a spoonful of mushroom "dirt" down the center of each of 4 rectangular serving plates. Add morels and asparagus to bowl with vegetables; drizzle with elderflower vinaigrette and toss to combine. Divide vegetable mixture evenly among plates; garnish each with a fennel chip. Garnish each plate with a dollop of marmalade; add herbs, flowers, and lettuces and serve.