Add the olive oil and butter to a large skillet over medium-high heat.
1 Tablespoon extra-virgin olive oil, 1 Tablespoon butter
When the butter melts, add the mushrooms, garlic, basil, and thyme to the pan.
8 ounces sliced mushrooms, 3-4 cloves garlic, ¼ teaspoon dried basil, ¼ teaspoon dried thyme
Cook for about 5 minutes, until the mushrooms release some liquid, the liquid evaporates, and the mushrooms develop a rich brown color.
Add the broth, ½ teaspoon kosher salt, and a pinch of black pepper. Stir and bring to a simmer.
½ cup low-sodium chicken or vegetable broth, kosher salt and black pepper
Add the cream, followed by the tortellini. Stir until the liquid is smooth and lightly coats all of the pasta, then reduce heat to medium-low and cover the skillet.
1 cup heavy cream, 18-20 ounces fresh cheese or spinach-filled tortellini
Cook for 5 minutes, then check the tortellini. If they’re not tender, return the lid and cook for about 1 minute more. (Check often and take care not to cook too long, or the sauce will separate. If you’re on the fence, go ahead with the next step.)
Remove the lid, reduce heat again to its lowest setting, and stir in the spinach and Parmesan. Let spinach wilt for about 1 minute. Season with additional salt and pepper to taste. Serve right away with more Parmesan, pepper, or herbs as desired.
2 generous handfuls fresh baby spinach, ¼ cup finely-grated Parmesan cheese