Process all pesto ingredients in a food processor until paste-like; set aside.
Cook pappardelle, corn, and green beans in a large pot of boiling, salted water until tender but not mushy, about 7 minutes; drain. (If using another pasta shape, adjust time as package directs. When 7 minutes are left in cooking the pasta, add the corn and green beans).
Combine ingredients for Tomato Garnish while pasta and vegetables cook.
To assemble, layer components by first placing ricotta in a large bowl; season with coarse sea salt and freshly ground pepper. Top with pasta and vegetables. Pour pesto over pasta and toss everything together. Sprinkle with Parmesan and tomatoes, then finish with olive oil, sea salt and pepper.