Heat olive oil in a pan over medium heat. Add onion then sauteed until translucent for about 3 minutes.
Add garlic, ground beef, and a pinch of salt. Sauteed for 3 minutes.
Add tomato paste, stir and cook for 1 minute until caramelized.
Add canned tomato, Italian seasoning, beef stock powder, and sugar, and then mix well. While stirring, crush the tomatoes using a spatula.
Adjust salt and black pepper to your taste. Then add water.
Cook for 1 hour in low heat and occasionally mixing until the sauce has thickened. Add more water in the between if necessary. Turn off heat. Set aside.
In a pan, melt butter over medium heat. After melted, add the flour and toast until the flour turns a little bit golden.
Reduce heat down to low, add 1/4 part of the milk while mixing so there is no lump on the saucepan. Once blended, add the remaining milk in 1/4 part increments, mixing well after each addition, until all the milk is used and sauce is free from lumps.
After the sauce thickens, add parmesan cheese and mix until the cheese is melted.
Preheat oven to 350°F or 180°C.
To assemble, add a layer of 1/4 part of meat bolognese sauce to a 7.5x9.5x2-inch glass rectangular dinnerware. Add lasagna sheet.
Add a layer of 1/4 part of meat bolognese sauce again. Then a layer of 1/3 part of béchamel sauce on top of bolognese sauce, then cover with lasagna sheets, thrice following with the order. Lastly, top with mozzarella cheese.
Bake for 25 minutes. Enjoy!