First Call is a weekly feature in which we walk into a bar and ask the bartender to make us his or her favorite drink.The Bar: Redwood, 514 E HowellThe Drink: Mini MargaritaThe Bartender: Petra (Last name withheld by request)Our story begins with shy young thing named Petra. She started bartending at Redwood three years ago to help pay for nursing school, and now works at a local hospital whose name she won’t allow me to use for fear that her fellow scrub-wearers will find out that she spends two nights a week slinging booze on Capitol Hill.I pop the question (Could you please, Ma’am, make me your favorite alcoholic beverage?), and she pours me a Hornitos margarita, a tiny one. “It’s my go-to shot,” says Petra. “Just the essence of the margarita without any of the filler.” By filler I think she means ice.I admit it, I was hoping for something a little more exotic, but as the woman sitting next to me — obviously a regular — rightly informed before downing the last of her PBR, the Redwood is a meat-and-potatoes kind of place. Tucked into the small residential belt between E. John and Pike-Pine, Redwood has a more relaxed atmosphere than one might find at the meat markets on the main Capitol Hill drags. It’s the kind of bar where graying neighborhood residents chill with heavily tattooed twenty-somethings and everyone eats free peanuts. Ambiance-wise, it’s Linda’s Lite. Before I can down the contents of my rocks glass, Petra comes by to ask if I wouldn’t prefer Redwood regulars’ current fav drink, which by her description I take to be some unholy marriage of bourbon and sweet tea. I pass it over in favor of the shot, and she nods in bashful approval. The tequila is cool and appropriately crisp going down, but not boozy enough to put me on my ass. It’s the perfect drink for people who can’t afford to be drinking, says Petra between beer pours. And that makes sense. Hornitos is a reasonably priced tequila, ideal for the financially challenged. Plus it disappears into the mixture, meaning you could probably ride the mini-margarita train all night if you’re the type who doesn’t want to taste his liquor. Being the kind of drinker who does, I decline a second and order up a microbrew.