How to Make It
Heat a small skillet over medium. Add 2 tablespoons oil; swirl to coat. Add onion and 2 tablespoons garlic; cook, stirring often, until lightly browned, about 10 minutes. Transfer onion mixture to a blender; add macadamia milk, pine nuts, 3 tablespoons nutritional yeast, 1 teaspoon salt, and pepper. Process on high speed until smooth, about 1 minute. Set aside.
Heat skillet over medium-high. Add remaining 2 tablespoons oil; swirl to coat. Add remaining 1 tablespoon garlic; cook until fragrant, about 30 seconds. Stir in panko, 1/4 teaspoon salt, and remaining 2 tablespoons nutritional yeast. Cook, stirring often, until panko is crispy and toasted, about 2 minutes.
Bring a large pot of salted water to a boil. Add carrots; cook 2 minutes. Add asparagus; cook 1 minute. Using a slotted spoon, remove vegetables to an ice bath. Let cool; drain. Stir in green peas.
Add pasta to boiling water; cook until al dente, about 12 minutes. Reserve 1/2 cup cooking liquid. Drain pasta, and return to pot. Stir in vegetables, tarragon, sauce, pasta cooking liquid, and remaining ¾ teaspoon salt. Cook over medium until heated through, 1 to 2 minutes. Spoon pasta into shallow bowls, and top with panko. Serve immediately.