Step 1

Preheat oven to 210C.

Step 2

Heat oil in pan, add onion, capsicum and zucchini.

Step 3

Stir over high heat for 3 minutes or until tender.

Step 4

Add tomatoes including liquid, reduce heat to low, simmer, uncovered, 3 minutes.

Step 5

Stir in tuna.

Step 6

Spread over base of a 1.5 litre ovenproof dish.

Step 7

Squeeze excess liquid from potato.

Step 8

Combine potato and cheese and spread over tuna mixture.

Step 9

Bake for 25 minutes.

Step 10

Place under hot grill until crisp and golden brown.