Heat sous vide bath to 171 degrees. Season octopus with salt and pepper, and drizzle with 1 tablespoon olive oil. Place in Ziploc bag or vacuum seal bag along with rosemary sprigs. Seal bag, squeezing out any excess air.
Cook in sous vide bath for 5 hours.
Remove octopus from bag and pat dry with paper towel. Cut cooked octopus into bite-size pieces.
Heat 2 tablespoons olive oil and garlic in skillet until hot and garlic is lightly browned. Add cooked potato and saute until heated through. Add octopus pieces. Season to taste with smoked paprika, salt and pepper. Toss octopus well.