Bring a large pot of salted water to a boil. Add the fettuccine and cook until al dente, about 8-10 minutes. Reserve ¾ cup pasta water, then drain and set aside.

In a skillet, heat olive oil over medium-high heat. Sauté asparagus, snap peas, zucchini, and mushrooms for 3-5 minutes until tender-crisp.

Add minced garlic, cherry tomatoes, spinach, and frozen peas. Cook for 2-3 minutes until spinach wilts.

In the same skillet, melt butter over medium heat. Whisk in flour until golden. Gradually add heavy cream and milk, whisking until thickened.

Remove from heat, stir in Parmesan cheese and lemon zest, adjusting seasoning with salt and pepper.

Add cooked fettuccine to the skillet, tossing until fully coated. Add reserved pasta water if necessary for consistency.

Transfer to serving plates and garnish with extra Parmesan and basil. Serve immediately.