The Somerville neighborhood of Union Square is small but mighty when it comes to a taste of Peru in Boston. At Celeste, a merengue-soundtracked, neon-lit space that’s hardly bigger than the open kitchen, you can enjoy Ceviche Mixed Seafood made with blue cod, shrimp, and squid; Lomo Saltado with stir-fried sirloin; and the Peruvian-Chinese style Sudado de Pescado (steamed blue cod). The right vibes extend to drinks: Celeste also serves what may be the best Pisco Sour in town. Don’t overlook the other cocktails made with the Peruvian spirit, though: We like Maracuya Sour made with pisco, passion fruit puree, egg white, lime, and amaretto. Co-founders Maria Rondeau and JuanMa Caldéron are keeping the party going: The duo just opened La Royal in Cambridge.