No. 7 is a comfortable restaurant with comfortable prices, but it is not doing comfort food. It is doing big-city, night-on-the-town chef food. The economy may be regressing, but that doesn’t mean our diets have to. Instead, No. 7 gives us sophisticated assemblages like slices of rare tuna fanned out with crisp, almost sweet Asian pear ($10). This appetizer looks utterly cool and composed, its rosy pink fish set off by the creamy white pear. But a shower of jalapeño oil knocks it off balance and starts a battle for dominance — hot? cold? — that, happily, is never quite resolved. No new ground is broken here, but the dish has a low-key tension that’s engaging, and characteristic of the approach taken by the chef, Tyler Kord.