Just boil the pasta and saute the vegetables, then toss everything together for this quick meatless meal.
Boil a large pot of salted water and cook pasta according to package directions. Drain, reserving 1 cup of cooking liquid. In a bowl, toss hot pasta and the ricotta cheese until combined.
Warm olive oil in a large skillet over medium-high heat. Add the garlic first, then the peas, salt, and pepper; sauté for about 4 minutes. Add reserved cooking liquid and continue cooking until peas are tender and bright green, about 4 more minutes.
Add the ricotta pasta to the pan; toss over low heat to combine. Add tomatoes and mix. Transfer to a serving bowl and sprinkle with lemon zest.