On a plate, toss the shrimp with the crushed red pepper, half the lemon zest, chopped herbs and a pinch of salt and pepper. Let it sit while you start the rest.
Bring a large pot of salted water to a boil and cook the angel hair until al dente, maybe 5 minutes. Drain all but about 1/2 cup of the pasta water.
Heat the oil in a medium skillet over medium-high. Add the garlic and swirl around for 30 seconds (careful not to let it burn!). Add the tomatoes along the remaining lemon zest. Sprinkle with a little salt and pepper and saute for 2 minutes.
Add the shrimp in a single layer and sear on one side for 2 minutes. Flip and sear another minute, or until shrimp is cooked through. Keep tossing the tomatoes just a little bit. When the shrimp is cooked through, toss it with the pasta, shrimp/tomato mixture, along with the spinach. Squeeze a lot of lemon juice right in. Season with coarse salt and pepper. Add as much pasta water as you want to create a thin, glorious sauce.
Serve it with more lemon juice, crusty bread and Parmesan/Romano cheese.