First, in a pot, boil the zucchini in salted water. Turn off the heat when the the zucchini tender
Second, remove the zucchini from hot water and cut each one in a half
Third, put the cut zucchini in a pyrex plate
Afterwards, in a pan on a medium heat, melt the butter and add the onion
When the onion start softening add the meat, the salt and the pepper, stir from time to time until the meat is cooked
Then add the tomato paste, stir for about one minute and turn off the heat
And add 1 tsp of this mixture to each zucchini
Now, add the Béchamel sauce
Then, add the mozzarella cheese
Finally. bake the preparation in the oven for 20 mins at 180 degrees Celsius (356 degrees Fahrenheit)