Put the broth and tomato paste in a small saucepan. Stir to dissolve the tomato paste. Gently warm the sauce.
In a large skillet or dutch oven, heat the olive oil and red pepper flakes, then saute the onions until soft and starting to change color.
Add the fideos and garlic, stirring to coat with oil.
Season with salt, pepper and smoky paprika.
Stir in the broth, red peppers and peas. Bring the liquid to a gentle simmer and cook uncovered until the fideos are almost ready. Add more broth or water as needed to prevent the noodles from getting dry.
Arrange the uncooked shrimp on top of the noodles and cover with a lid. Allow to warm through (add the shrimp earlier if uncooked).
When the shrimp are ready, stir to combine, taste and adjust seasoning. Garnish with parsley before serving.