In the past year Trattoria Marcella has expanded (for the second time in a decade) -- and the space still isn't big enough to contain the aromas emanating from the kitchen. The delicious smells sneak through the cracks and spill into the neighborhood in which Marcella resides, on the far western downslope of the Hill. If you're looking to impress someone -- your date, your parents, your snobby and skeptical New York City client -- they'll be sold before they even walk in the door. Marcella's newfound girth was necessary; the place bustles nearly every night and is one of the toughest prime-time weekend tables in town. Mayor Slay is a regular. In addition to offering some of the best Caesar and spinach salads in town, chef Steve Komorek makes superior calamari, which he serves with gently flash-fried spinach and lemon quarters. When it comes to pasta, chef Komorek shines with tomatoes, but we prefer his remarkable farfalle Alessandra: bow-tie pasta tossed with smoked salmon, asparagus and black olives in a gentle lemon-cream sauce. It's rich, and buttery, but well worth the hour it'll eat off the end of your life. We could continue piling superlatives on this St. Louis gem -- the staff, the wine list, the dessert menu -- but all this talk of Marcella is making us drool. On top of it all, "not cheap" doesn't mean "prohibitively expensive": Pastas here range from $12 to $20 for a feast, and the meat and fish entrées run from $15 to $25.