Add the oil, butter, and onion to a pot over medium-high heat. Sauté the onion for 3-4 minutes.
Add the garlic, Italian seasoning, sun-dried tomatoes, lemon juice, Dijon mustard, and orzo. Cook for 2-3 minutes, stirring often to infuse the orzo with the flavors.
Add the chicken broth and cream. Once it starts to bubble, continue cooking for 10 minutes (uncovered), stirring fairly often. You will likely need to turn the heat down a bit (to medium or even medium-low). It should steadily bubble (not furiously boil), and you don't want the liquid to cook off too much before the pasta is done.
Take the pot off the heat, and stir in the parmesan, spinach, and basil. Cover the pot for a few minutes until it has thickened up to your liking. The orzo will absorb the liquid quickly, so if it still seems like there's too much liquid, just wait a little bit longer. Season with salt & pepper as needed.
Notes
Serves 6 as a side or 4 as a main course (you may want to serve it with garlic bread and/or a salad).
I used sun-dried tomatoes that are packed in oil and drained the oil prior to adding them to the pot. You can always add more if you really love them!
Troubleshooting tips: Since every stove and pot can vary, use your best judgement when making one pot pastas. If it looks like the liquid is running out before the pasta is cooked, add a little more broth in (a half cup or so at a time). Conversely, if the cooking time has elapsed and there's still too much liquid, just let it sit for a little longer and the orzo will absorb it.
This recipe also is in chapter 6 of the Salt & Lavender: Everyday Essentialscookbook.