Question: When removing top hand-width of lawngrass by bulldozer, does it stay away for some time t

I tried to dig the lawn out this summer, by hand, but everything grew back quickly. Normal northern european lawngrass, not the tropical devellish kinds.

If you have experience with the following, please answer my question:
If i use a bobcat or bulldozer to remove the lawn (scraping a handlength of the top and taking it away) and plant it densely with vegetables and keep the ground covered with mulch, will the grass grow back quickly or do i have several years without any grass?

It won't come back at all with that method, but you will have lost your best soil. Grass seeds will be present however and they will germinate you will always need to keep on top of them.
If you are in Northern Europe(or similar climate) then get some cardboard and put that down now, cover it in mulch to keep it from blowing away, the grass will die over winter and by around April you can plant what you want. If you have black plastic you could use that instead, since you will be removing the plastic before planting I would leave it until May if you get it down now.

How deep is your topsoil? If you remove all grass and roots it would probably not come back, however around me that would remove all topsoil and nothing would grow. Also other weeds could blow in and become problematic over time. What about putting down something as a ground cover to smother it out? Then plant when it is dead or depending on the cover plant through it.

I have best success removing sod in whatever method is most efficient for the size area; by hand or by bobcat etc; making sure I dig down far enough to grab all the root o can. Then placing a barrier down; recently I used brown craft paper by the roll.  Then I replace the soil I have extricated with ( hopefully) weed free grass free topsoil and 5hen maintain a thick layer of mulch.

If grass returns I pull it and heavily mulch that spot.  

I would still mulch even with a heavy planting of anything; vegs or flowers.

Janet Reed, i have previously removed grass by hand, put in cardboard and on top of that bought in plant dirt from the supermarket..... resulting in lots of grass, so i gather that the dirt had lots of grass-seeds in it. Not going to do that again. This time i'll attempt like you have tried, removing the grass, and planting straight in it.

Anyone else have tried this?

No.....I removed the sod; put down cardboard, paper etc.  then put in good topsoil and lots of mulch.  Mulch is the key. As is the mulch under the topsoil.  It doesn’t meAn you won’t get grass..but if you dig the sod out completely...and realize how deep the roots are;  you should get very little grass. If you do...pull and mulch.