From domestic gate to CCR there's only a scan of the boarding pass, and it will take you just over 5 minutes to get from the aircraft to the CCR. From CCR to departure gate - well obviously it depends on the gate but if using the passageways (guide in the Dashboard) no gate is more than 15 minutes walk from CCR. Since the cut off for last boarding is 20 minutes, then leaving 40 minutes before departure should be fine. So anything over 45 minutes or so between flights can be lounge time.

The menu items are designed to be served fast, cold items tend to appear in under 5 minutes, hot items about 10 minutes. Usually I would recommend you to just order say the soup or a cold starter and a hot main together and you would then get the first 2 courses in well under 30 minutes. Then order the dessert / cheese. So anything over 90 minutes between flights - assuming an on time arrival from the domestic gate and things like 767s / bus arrival-departure can complicate this - would be the direct answer to your question. If you wanted a hot starter then I would order course by course, otherwise the dishes tend to all arrive together, but it doesn't change the timescale by very much.

Personally I think if you are new to the CCR, a 2 hour DOM-INT connection is perfect - it will give you an unrushed visit and plenty of time to eat and drink, but it will go quite quickly so you'll have something to look forward to on your next visit.