Arrange the slices of chorizo in the center of a baking tray and surround with the chicken thighs.
Quarter the tomatoes, potatoes, and onions and cut the yellow pepper into strips. Place each in one of the four corners of the tray. Add a whole garlic clove to each vegetable.
Drizzle all of the ingredients with olive oil and season with salt, pepper, oregano, and paprika. Garnish with fresh sprigs of rosemary. Bake in the oven at 350°F for 20 minutes.
Remove and turn the meats over, then continue baking for a further 10 minutes.