The first step is to cook the pasta. Boil the water and add olive oil and salt. Once the water is boiling, add the pasta shells. I like my pasta al dente so I cook the shells for about 7-10 minutes. While the pasta is cooking, wash and dice all the vegetables and set aside.
On the stove over medium-high heat place a large skillet and add the butter and mushrooms. Stir for about 1-2 minutes. Then, add the peppers, tomatoes, garlic, Italian seasoning, basil, and cilantro.
Add marinara sauce and about a ½ cup water from the pasta that is boiling. Cook all for about 3-4 minutes.
While the sauce is cooking, boil the pasta.
Next, drain all the water from the pasta and combine it with the sauce. Let it cook for about 5 to 10 minutes.