📖 Instructions

1. Bring a large pot of salted water to a boil. This will be for cooking the pasta. Don't skimp on the salt; it seasons the pasta from the inside out.
2. While the water is heating, prepare the rainbow chard. Wash it thoroughly, then separate the stems from the leaves. Roughly chop the stems and leaves separately. The stems take a bit longer to cook, so they'll go in first.
3. Once the water boils, add the pasta and cook according to the package directions until al dente. This usually means cooking it for a minute or two less than the recommended time, as it will continue to cook a bit in the skillet. Reserve about 1 cup of pasta water before draining. This starchy water is liquid gold for creating a creamy sauce.
4. While the pasta is cooking, heat olive oil in a large skillet over medium heat. Add the chopped rainbow chard stems and cook for about 3-5 minutes, until they start to soften. Stir occasionally to prevent burning.
5. Add the chopped rainbow chard leaves to the skillet with the stems. Cook for another 3-5 minutes, until the leaves are wilted and tender. Stir frequently. If the skillet seems dry, add a splash of olive oil or a little pasta water.
6. Stir in the minced garlic and red pepper flakes (if using) into the skillet. Cook for about 1 minute, until fragrant. Be careful not to burn the garlic, as it can become bitter.
7. Zest and juice the lemon. Add the lemon zest and juice to the skillet with the chard. Stir to combine. The lemon juice will deglaze the pan and add a bright, tangy flavor.
8. Drain the pasta, reserving about 1 cup of the pasta water. Add the drained pasta to the skillet with the chard and lemon mixture. Toss to combine.
9. Add about 1/2 cup of the reserved pasta water to the skillet. Toss continuously until the sauce thickens and coats the pasta evenly. Add more pasta water, a little at a time, if needed. This step is crucial for creating a creamy, emulsified sauce.
10. Remove the skillet from the heat. Stir in the grated Parmesan cheese (or vegan alternative) and butter (if using). Toss until the cheese is melted and the butter is emulsified into the sauce. These additions will add richness and depth of flavor.
11. Season with salt and black pepper to taste. Remember that the Parmesan cheese is already salty, so start with a small amount of salt and adjust as needed.
12. Serve immediately, garnished with extra Parmesan cheese, a drizzle of olive oil, and a sprinkle of fresh parsley or basil, if desired. A squeeze of lemon juice right before serving can also brighten the flavors even more.