Heat a large pot over medium-high heat. Add chorizo and break up with a spoon. Cook until browned, about 5 minutes.
Add onion and cook until softened, 4 minutes. Stir in garlic and paprika, cook 1 minute.
Add beans and stock. Bring to a boil, then reduce to a simmer. Cook 15 minutes.
Stir in kale and cook until wilted, 3 minutes.
While stew simmers, heat olive oil in a small skillet over medium heat. Fry sage leaves until crispy, about 30 seconds per side. Drain on paper towels.
Ladle stew into bowls. Top with crispy sage and serve with lemon wedges.