Prepare pizza crust according to package directions. Brush with 1 tablespoon olive oil and spread spinach over top.
Combine remaining 1 1/2 tablespoon olive oil, red onion, garlic, tomato, leeks, tuna, and salt in a small bowl. Spread evenly over pizza crust. Top with crumbled feta cheese and shredded Parmesan cheese, if using.
Bake in preheated oven 15 minutes, or as directed on crust package. Slice and serve!