A few of my favorites in Lisbon (and surrounding areas):

Food: Oven Lisboa (Indian and Nepalese), Sem (elevated Portuguese no waste restaurant specializing in fermented foods), Mezze (Syrian), Luka (Asian), Pomme Eatery (small plates), Las Gringas/Duro De Matar (Mexican taqueria) Aura Dim Sum, Kefi Greek Bistro, Heim Cafe (cute brunch spot, get there early to avoid a wait), Lupita (naturally leavened pizza), The Folks (brunch), Rhodo Bagels, A20 (try the pastrami sandwich and specialty coffee) Pita.gr (Greek, located in Caparica), Blitz Pizza (incredible pizza in Caparica)

Dessert: Manteigaria (pastéis de nata are best eaten hot), Do Beco (slow fermentation bakery & restaurant), Bike Bakery, Chocolataria Ecuador (despite the name they are made in Portugal), Santini Ice-cream , Gleba (for cookies and fresh bread), Juliana Penteado Bakery, Nivà Cremeria Gelateria Italiana

Coffee: Copenhagen Coffee Lab and Bakery (get their cinnamon roll), Marquise da Mobler (aesthetic cafe with lush back patio and good pastries), Fabrica

Things to see: Classically Portuguese park Miradouro de São Pedro de Alcântara with beautiful views of the city, Estufa Fria botanical garden, Ler Devagar bookstore, Fundação Calouste Gulbenkian art museum and gardens, Boca do Inferno in Cascais, Palácio Nacional da Pena and Quinta da Regaleira in Sintra

Beaches in driving distance: Praia do Ribeiro do Cavalo and Praia das Bicas near Sesimbra, Praia de Galapos in Portinho da Arrábida, Praia da Mata in Caparica