Directions:

Cook the pasta in a large pot until it is al dente. Dice the onions and garlic close to the same size. Strain the pasta over a cup or bowl to save some of the pasta water. In the same pot brown the butter. Then add the onions and saute until softened. Add the garlic and flour to make a roux. Constantly stir until fragrant and flour is browned. Then add small amounts of the pasta water until the sauce is your desired thickness. Finally add the raw shrimp and spinach to the sauce. Simmer until the shrimp are fully pink, then add the pasta. Mix everything together and serve.