Mexican Food Week continues with Little Café Poca Cosa. Chips and salsa. And a tall aqua fresca. Now that’s what I call a great beginning to breakfast. When Sandra asked me what I wanted to drink, I remembered the great agua fresca I’d had here a year earlier: limón con hierbabuena (key lime with peppermint.) I also remembered my less-than-successful attempts to recreate it at home. Today’s choice: Key lime with basil. Other flavors on offer this morning: mango-peach, pineapple with basil, lemon with strawberry, horchata (rice and cinnamon) and three or four others. Concocted from water (3 cups), sugar (1 cup) and either fruit (watermelon, strawberry and cantaloupe are standards; about 3 cups), seeds or grains, these non-alcoholic drinks are often sold by street vendors throughout Mexico as well as in restaurants and cafes. (I stopped at a taqueria later in the day and had a tamarind-flavored one.) A squeeze of lime, some salt, some herbal enhancement, the offerings are as inventive as the ingredients at hand and the individuals who set about combining them.