Combine rice vinegar, water, sugar, and kosher salt in a small saucepan. Warm over medium heat, stirring, until sugar and salt dissolve. Remove from heat and let cool slightly.

Place thinly sliced watermelon radish in a jar or shallow bowl. Pour warm pickling liquid over the radishes, pressing to submerge. Let cool to room temperature, then cover and refrigerate at least 30 minutes (preferably 1–2 hours) while preparing other components. Keep refrigerated until plating.

Beet Purée

Place cooked chopped roasted beets, water or stock, lemon juice, salt, pepper, and olive oil in a blender or food processor.

Blend until completely smooth, adding an extra teaspoon of water or stock if needed to reach a silky spoonable consistency. Pass through a fine mesh sieve for an extra-smooth texture, if desired. Keep refrigerated or warm gently in a double boiler until serving.

Fennel Citrus Cream

In a small saucepan over low heat, combine thinly sliced fennel and heavy cream. Warm gently until the cream barely simmers and the fennel softens, about 6–8 minutes, stirring occasionally.

Remove from heat and let steep for 10 minutes to infuse fennel flavor. Transfer mixture to blender, add lemon juice, orange zest, salt, and white pepper, and blend until smooth and slightly aerated. If too thick, thin with 1–2 teaspoons of water or cream. Keep warm (lid on) until plating.

Mushrooms

Heat 1 tablespoon olive oil and 2 tablespoons butter in a large skillet over medium-high heat until butter foams.

Add minced shallot and cook 1–2 minutes until translucent. Add minced garlic and thyme; cook 30 seconds until aromatic.

Add torn blue oyster and shredded lion's mane mushrooms in a single layer (do in batches if necessary). Let cook undisturbed 2–3 minutes to brown, then stir and cook another 2–3 minutes until golden and tender.

Deglaze the pan with white wine (if using), scraping up browned bits. Stir in soy sauce, adjust salt and pepper to taste. Remove from heat and set aside, keeping warm.

Pasta & Assembly

Bring a large pot of salted water to a rolling boil. Cook tagliatelle according to package instructions until al dente. Reserve 1 cup pasta cooking water, then drain pasta.

While pasta is hot, return the pot to low heat. Add ricotta, 3 tablespoons butter, half of the grated Parmigiano, lemon zest, and 1/2 cup of the reserved pasta water. Stir vigorously to create a creamy sauce; add more pasta water as needed to reach a silky coating.

Add drained pasta to the ricotta sauce and toss gently to coat evenly. Taste and adjust seasoning with sea salt and black pepper.

To plate: Spoon a smear or small pool (about 2–3 tablespoons) of beet purée on each plate. Nest a portion of the ricotta-coated pasta on top of the beet purée.

Arrange warm mushrooms on and around the pasta. Spoon or dot fennel citrus cream around the plate (use a spoon to create teardrops). Add several slices of pickled watermelon radish on top for brightness and crunch.

Finish with remaining grated Parmigiano, chopped toasted hazelnuts, microgreens or fennel fronds, a light drizzle of extra-virgin olive oil, and an extra sprinkle of lemon zest and chives.