We visited the Chalet Dent de Vaulion on Sunday. If you are looking for an alpine restaurant that offers views with very little walking then this one hits the mark.  The restaurant is just a 15 minute "hike" from the summit of the Dent de Vaulion and can easily be driven to with a parking lot just out front.  The restaurant is at an altitude of 1420 meters and is open every day from April to October.
Since so many of the mountain restaurants are closed in the month of April it is nice to have an option of somewhere to visit during this "off-season".  And since it isn't too high in altitude you can go earlier in the season without the worry of snow or being too cold.
On a bright and sunny day in the first week of May 2018
It is a typical mountain chalet with the majority of seating outside on the deck.  We were lucky to get a table as we arrived early in the day (10:30 AM) which gave us plenty of time to walk up to the summit, relax at the top and then return before the lunch rush arrived.    
View of the front of the restaurant from the parking lot
We parked near the restaurant and took the short walk to the peak which took us about 25 minutes (as we walked very leisurely with me being 7 months pregnant and Lucas having fun stopping to throw rocks several times).  The summit, at an altitude of 1483 meters, is easy to reach by walking just behind the restaurant and up the hill.  You don't have to work very hard to get great views and  benches to relax on:
Taking in the views after the short walk from the restaurant
We spent about 45 minutes admiring the all-round panoramic views of the Alps, the Jura, and the lakes of Geneva, Neuch√Ętel and Joux:

Eliana and Lucas resting under the metal pyramid marking the summit of Dent de Vaulion
After enjoying the views at the summit and allowing the children to climb on the old stone wall we meandered our way back down to the restaurant where we enjoyed a typical alpine meal of fondue, cured meats and cheeses, beers followed by coffees and desserts. 
Walking back down from the summit - restaurant can be seen in the distance
View of the back of the restaurant while heading back down from the summit
Happy to be eating outside on a bright and sunny May day

Photo Credit: Eliana.  Summit seen behind us

Enjoying a swing located just behind the restaurant

Many hikes lead to and from the restaurant