Wash and prepare all vegetables: trim and cut asparagus into 1-inch pieces. Dice zucchini and bell pepper into 1/2-inch cubes. Halve the cherry tomatoes. Mince the garlic and finely dice the shallot. Zest the lemon (about 1 tbsp) and then juice it (about 1/4 cup). Chop fresh parsley, basil, and oregano.

Bring a large pot of generously salted water to a rolling boil. Add the linguine and cook according to package directions until al dente. Before draining, reserve 1 1/2 cups of the starchy pasta water. Drain the pasta and set aside.

While the pasta cooks, heat the olive oil in a large skillet or Dutch oven over medium heat. Add the diced shallot and cook for 2-3 minutes until softened and translucent.

Add the minced garlic and red pepper flakes (if using) to the skillet. Cook for another 1 minute until fragrant, being careful not to burn the garlic.

Stir in the asparagus, zucchini, and bell pepper. Cook for 5-7 minutes, stirring occasionally, until the vegetables are crisp-tender.

Add the halved cherry tomatoes and baby spinach to the skillet. Cook for 2-3 minutes, stirring constantly, until the spinach has wilted and the tomatoes have just started to soften.

Pour in the reserved lemon juice and add the lemon zest. Stir in the chopped fresh parsley, basil, and oregano. Season with 1/2 teaspoon of salt and 1/4 teaspoon of black pepper, or to taste.

Add 1 cup of the reserved pasta water to the skillet. Bring to a gentle simmer, allowing the sauce to slightly reduce and thicken for about 2-3 minutes. If the sauce seems too thick, add a little more pasta water, 1/4 cup at a time.

Add the cooked and drained pasta directly to the skillet with the vegetable sauce. Add 1/2 cup of grated Parmesan cheese. Toss everything together vigorously for 1-2 minutes, allowing the pasta to absorb the flavors of the sauce and the cheese to melt and create a creamy consistency.

Taste and adjust seasonings as needed. Serve immediately, garnished with additional fresh herbs and a generous sprinkle of grated Parmesan cheese.