Bring a large pot three-fourths full of salted water to a boil. Add the pasta, stir well, and cook until just tender but still firm to the bite, about 11 minutes.

Meanwhile, heat the eggplant, pepper, and tomato sauce in a large nonstick skillet over medium heat until warmed through.

Reserve ½ cup of the pasta cooking liquid, and then drain the pasta. Add the pasta to the sauce, and stir to coat, adding pasta cooking liquid if needed to moisten. Add the cheese and toss just until starting to soften. Divide the pasta and sauce between 2 warmed bowls. Sprinkle with marjoram and serve right away.