Polenta and avocado bites

Spray the base and sides of a deep 20cm (8-inch) square cake pan with a little cooking oil. Spread the polenta with a spatula to make sure the top is smooth and level.

Put the water in a medium saucepan. Turn on the stove to high and boil the water. Gradually add the polenta to the water; stir it in with a wooden spoon. Turn down the heat so the polenta is simmering. Continue to stir for about 10 minutes or until the polenta is thick. Take the saucepan off the heat. Add the cheese; stir until cheese melts. Spread the polenta into the cake pan with a spatula; let it cool down for 10 minutes. Cover the pan with plastic wrap; put it in the fridge for about 1 hour or until the polenta is firm.

Use a small knife to carefully cut avocado in half, around the seed; scoop the seed out with a spoon. Scoop the avocado flesh out of each half with a spoon and put it into a small bowl with the lemon juice; mash with the back of a fork until the mixture is almost smooth.

Take the polenta out of the fridge. Carefully turn the polenta out of the pan onto a board; cut the polenta into 36 small squares; cut the whole large square into six even strips, then cut each strip into six squares. Put the oil in a large frying pan. Turn the stove on to medium and heat the pan. Put the polenta into the pan and cook, turning with tongs, until it is browned all over.

Take the polenta squares out of the frying pan; put them onto a plate. Spoon a little of the avocado mixture on top of each polenta square. Top each square with a tomato half.