Bring a large pot of water to a boil. Add a hefty pinch of salt, then the pasta, and cook according to directions

Meanwhile, heat a large skillet over medium-high heat, add a glug of olive oil and, if using, a sprinkle of the red pepper flakes. Cook for about 30 seconds, then add the chard, and a pinch of salt. Cook, stirring to break down the chard

When the pasta is done, add it directly from the water into the pan of chard, bringing some of the pasta water along with it. Add in about ¼ pouch of Romesco sauce and stir to coat and combine everything. Cook for a few more minutes to thicken up the sauce

Serve tossed with an extra squeeze of Romesco and the toasted nuts