Pizzerias and burger joints have been around for decades. But the prevailing winds of economic uncertainty seem to have carried the streamlined menu into entirely new realms. One notable example: This spring’s opening of Medium Rare in Cleveland Park. At this restaurant, dinner is essentially decided before you arrive: You get salad, bread, steak, fries, and a smothering of savory mushroom gravy. That’s it. If you’re still hungry, you get a second helping of steak for no additional charge. Your only choices involve the temperature of the meat and what to drink with it. Skip the wine and you can escape for less than $20. It’s the very façade of a refined French bistro stripped down to Applebee’s-style affordability, which is precisely the sort of thing people are looking for in this era of pseudo-austerity. By year’s end, the joint’s backers were also helping Michel Richard, one of the city’s fanciest chefs, start his own single-dish eatery. It serves meatballs.