Preheat oven to 400 degrees. Bring a large pot of salted water to boil for your pasta. Keep the choy sum whole and drizzle with olive oil, salt and pepper. Roast until just starting to char, 15 minutes, turning the veggies once, halfway through baking. While that’s happening, cook your pasta until 1 minute less than fully cooked. Set aside a cup of pasta water and drain the rest.

Transfer your roasted choy sum to a food processor with the juice of half a lemon, a clove of garlic, and a drizzle of extra virgin olive oil. Pulse until well blended.

In a large skillet, heat a tablespoon o33f olive oil and add the onion and 2 cloves chopped garlic. Cook down until golden and tender, 7 minutes. Add the cream, pasta, choy sum mixture, lemon zest, and crushed red pepper flakes. Stir all together. Loosen it up with some of the reserved pasta water if necessary, and adjust seasoning if needed. Serve sprinkled with Parmesan and toasted sunflower seeds.