Makes 6 servings.
Heat oil in large nonstick skillet over medium heat. Add onion and sauté until tender and golden, about 10 minutes. Add garlic, thyme and crushed red pepper and stir 1 minute. Add squash and lima beans and sauté 3 minutes. Add 2 cups broth and bring to boil. Reduce heat, cover and simmer until vegetables are tender, about 6 minutes. Season to taste with salt and pepper.
Meanwhile, cook pasta in large pot of boiling salted water until just tender but still firm to bite, stirring occasionally. Drain. Return to pot. Add squash mixture to pasta. Toss to blend, adding more broth by 1/4 cupfuls to moisten if necessary. Season with salt and pepper. Transfer to bowl. Sprinkle with Parmesan cheese.