Excuse me if I am wrong but my Indian friends have a small spice kitchen that is vented separately and is in a small space that is closed and then the main kitchen is open with another stove and venting system. it seems to work quite well

well, i'd have a hard time running between the two areas cooking; my best guess would be have your cooktop be in the far corner, have a good venting system, and remember to turn on the vent before you turn on the stove, getting the airflow going the right direction before food hits the hot pan.

A separate area with a stove, cutting area, small sink is one idea and with a wide doorway using French doors perhaps, it wouldn't feel closed in. Better option than having a totally closed in kitchen if your heart is set on an open concept. (Ignore the stove's location below...but hope the concept of the additional room helps with envisioning the concept and flow).

thank you all of you but I want to stay on open one but I don't know how to do it in the right way

The vent hood isn't the sole factor. Is there an enclosure left and right of the cooktop to help contain smells and funnel them through the hood? How high is the hood mounted? Are there enough CFM's? (Powerful hoods may require makeup air too.) How short and direct is the ducting? I don't know that there's a perfect design to eliminate 100% of odors, but I would start with these questions when working through your kitchen design. Good luck!

simstress the point as you said if the vent hood is very powerful it's ok in this case !

no matter how strong the hood is, foods that are fried and use lots of spices will make the house smell of everything you cook.