Preheat the oven at 200 degree Celsius.
Cut the onion in small pieces.
Fry the minced meat and the onion half done in a frying pan.
Add the taco spices in the casserole, and mix it together. Add 200 ml water and lower the temperature, and boil away the water.
Put 1/3 of the lasagna plates in an oven form.
Add half of the minced meat on the lasagna plates and spread it evenly.
Spread half of the tomato sauce on the minced meat.
Make another layer with lasagna plate, the rest of the minced meat and the tomato sauce like above.
Put the last lasagna plate on top of the lasagna, and spread the cheese on top of it.
Put the lasagna in the middle of the oven for approx 45 minutes.
Take out the lasagna of the oven and serve it warm.