Bring a pot of lightly salted water to a boil. Cook angel hair in the boiling water until cooked through yet firm to the bite, 4 to 5 minutes; drain. Divide between 2 plates and keep warm.
Heat olive oil in a skillet over medium heat. Cook and stir onion in the hot oil until softened, about 3 minutes. Stir curry powder into the onion; cook and stir 1 minute more.
Transfer the onion mixture to a blender; add 1/4 cup chicken broth along with evaporated milk and tomato paste.
Return the skillet to medium heat. Sear scallops on each side in the hot skillet, 2 to 3 minutes per side. Place scallops atop the angel hair pasta; keep warm.
Pour 1/4 cup chicken broth into the pan; bring to a boil while scraping the browned bits of food off of the bottom of the pan with a wooden spoon. Pour the contents of the skillet into the blender; blend until smooth and return the mixture to the skillet. Simmer the sauce until warm; pour over the scallops and pasta to serve.