Cook the sausage: heat 1 tablespoon olive oil in a 20cm (8-inch) non-stick pan over medium heat. Add chicken sausage slices and cook 3 minutes until browned. Remove and set aside.
Cook the vegetables: in the same pan, add remaining olive oil. Add onion and cook 2 minutes. Add zucchini and garlic, cook 4-5 minutes until the zucchini is just tender and any moisture has evaporated. Season with salt, pepper, and smoked paprika. Return sausage to the pan and distribute evenly.
Make the egg mixture: beat eggs with chives, a pinch of salt, and black pepper. Pour over the vegetables and sausage in the pan.
Cook low and slow: reduce heat to low. Let the eggs cook undisturbed for 4-5 minutes until the edges are set and the center is still slightly loose. Use a fork to gently open spaces between the cooked egg and the pan edge so the liquid runs underneath.
Flip: place a large plate or lid over the pan. In one confident motion, flip the tortilla onto the plate. Slide it back into the pan uncooked-side down. Cook 2 more minutes until fully set.
Rest and serve: slide onto a cutting board. Rest 2 minutes before slicing. Serve with sliced avocado seasoned with salt, pepper, and a squeeze of lime.