Add the flour, yeast, salt to a bowl and mix well. Add the olive oil and the plant-based milk and incorporate everything together until it forms a non-sticky dough. Knead it for about 10 minutes.
Place the dough back to the bowl, cover and leave to proof for 40 minutes in a warm place.
After 40 minutes, remove the dough from the bowl, deflate it and cut into 4 equal pieces. Make a ball with each piece, then flatten it with a rolling pin, add the hamburger patties, the tomatoes, vegan cheese, onions, and oregano.
Close the dough by folding the ends and make sure there are no holes in your dough, otherwise, the cheese might escape when in the oven.
Mix the vegan mayo and the ketchup in a small bowl and brush it on top of each calzone, then sprinkle the sesame seeds.
Put the hamburger calzones in a 365F preheated oven for about 20 to 25 minutes. When ready, remove from the oven and wait at least 10 minutes before serving.