Combine potatoes, oil, 1/2 teaspoon salt, and 1/4 teaspoon black pepper in a large roasting pan, tossing well to coat potatoes. Arrange potatoes in a single layer, cut side down, in pan. Bake at 400° for 15 minutes or until potatoes are lightly browned.
While potatoes cook, peel shrimp, leaving tails intact. Devein shrimp, if desired. Set shrimp aside.
Stir chorizo, green beans, garlic, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon black pepper into pan. Bake at 400° for 10 minutes. Add beer, paprika, and bell pepper, scraping pan to loosen browned bits. Nestle shrimp into vegetable mixture. Bake at 400° for 10 minutes or until potatoes and green beans are tender and shrimp are done. Sprinkle with fresh parsley leaves.