Here’s where it gets interesting. Instead of just squeezing some lemon juice over the pasta, or grating lemon zest, we are sautéing thin slices of lemon until they are well browned and caramelized. Those sautéed lemons slices get minced and added to everything else. The browned lemon bits bring zippy bursts of roasted lemony flavor to the dish, providing a wonderful accent to the shrimp, spinach, and linguine. Try it, you’ll see! Just make sure the lemon is very thinly sliced and that you sauté it long enough to get thorough browning. Add the thinly sliced lemons to the pan and cook until browned and softened, 7 to 8 minutes. Remove from pan, set aside to cool. Once the lemon slices are cool, mince them. Add the garlic and cook a minute more. Serve immediately. Sprinkle with grated Parmesan cheese to serve.