Preheat oven to 180 °C. Spray a large ovenproof dish with olive oil and set aside.
Bring a saucepan of unsalted water to the boil and cook pasta according to packet directions. Add peas for the last minute of cooking time. Drain pasta and peas, reserving ⅓ cup of the cooking liquid.
While pasta is cooking, heat oil in a large pan over medium-high heat. Cook spring onion, garlic and chilli flakes, stirring for 3-5 minutes or until softened. Add chopped tomatoes and cook for 3-4 minutes or until mixture slightly thickens. Set aside.
Combine the pasta, peas, spring onion mix, cherry tomatoes, basil, lemon zest, rocket, tuna and reserved cooking liquid in a large bowl. Toss to combine. Season with cracked black pepper.
Spoon pasta mixture into the prepared dish and sprinkle with cheddar cheese. Bake in the oven for 20 minutes or until cheese is golden brown.
Allow to cool. You can either freeze the pasta bake in the ovenproof dish that it was cooked in or portion out the pasta bake and freeze in individual freezer bags or airtight containers.