I have been splitting my time between a small town in Northeastern Espirito Santo and Boston. Outside Brazil Espirito Santo is not all that well known, although its offshore petroleum, its exported granite, and other exported products (coffee, coconut water, charcoal, cellulose) find themselves across the globe. Within Brazil Espirito Santo is affectionately known as Minas Gerais' beach, much like the relationship of the communities on the North Sea to Germany, Belgium, and central European countries. Geographically ES is commonly discussed as Northern ES and Southern ES, the Northern part comprised of the more agricultural regions stretching from Vitoria to the borders with Minas Gerais and Bahia. I am mostly going to talk about the Northeast (closest to Bahia) and not discuss the South which includes some of the largest oil producing fields (on RJ/ES border) and the large resort town of Guarapari.
In Brazil Espirito Santo is most well known for its entry in the competition of Moquecas between Bahia and Espirito Santo -- the moqueca capixaba, made in the handmade clay pots "panelas de barro." The panela de barro, as well as names invoking Minas Gerais and to a lesser extent the wood stove (fogao a lenha most commonly associated with Minas) are commonly used in restaurant names. If you are travelling to the Northeast Espirito Santo and arrive by plane, you will land in Vitoria. The airport itself is very close to the bairro Goiabeiras (about 10 minutes by taxi) which is known for its "paneleiras" (pot makers) who sell their wares alongside the road and have formed a trade association representing them. So its easy to make a quick side trip there, although the pans can be bought across the region both in small stands in the summer, craft stores (artesenatos), and in highway-side stores. The cities of ES are linked with cities all over Brazil by bus, but in Brazil buses stop at well equipped truck stops (parados do onibus) and in ES these usually sell panelas de barro at a small premium over the ones roadside. If you do invest in a clay pot, keep in mind that they should be seasoned, that quality varies significantly, and before making an expensive moqueca (I have seen people waste $100 of fresh striped bass) make something inexpensive like rice just to be certain you are not getting off flavors. Packing them for travel is another topic altogether.
The Moqueca in Espirito Santo differs from the Moqueca Baiana in the use of olive oil (called azeite doce or sometimes neutral oils) instead of Dendê (palm oil), the use of urucum for coloring (annato, sometimes paprika) often in oil form, and the lack of coconut milk. Something interesting is that in the Northeast these rules are not as firm as they are in the Southern part, a few capixabas (not Bahian expatriates) add coconut milk. There are similar differences between Bahia and ES in making Bobó de Camarão (a yuca and shrimp stew), although the addition of coconut milk in ES is more common than in a moqueca and I have even heard one capixaba cook say she likes the taste of dendê in bobó. Another signature of Espirito Santo is the Torta Capixaba featuring assorted seafood and hearts of palm (palmito) which you will see a lot around Vitoria and in Guarapari and is traditionally eaten during Semana Santa -- from Palm Sunday through Easter. Interestingly its not something seen much on menus in the North and several cooks I asked professed not knowing how to make it. Lastly some of the mariscos (shellfish) used in it are less common in the Northeast, so it could be something which is more common in the South or maybe during Lent it does appear more. Lastly crab (siri & caranguejo) appears all over the place in ES -- its pretty exciting to order a shredded crab pastel (pastelao de siri catado) in a dirty bus terminal and get one with fresh lumpy crabmeat. And salt cod, despite the expense, is popular along with palmito.
Ethnically in Espirito Santo Italian immigration has made a large mark on the culture. A huge percent of the population are descendents of Italian immigrants. This includes areas like Santa Teresa (North of Vitoria) where Italian traditions are on display (architecture, festivals, wine making, street food like fried polenta). However, all across the state these traditions have a more subtle influence: people who mix beans and pasta instead of eating with rice, communities which have special pastas they make and serve in broth made with stewing fowl. When you get outside the cities into the agricultural areas, these influences are seen. There are also several large communities with descendents from Germany, including communities where a German-Portuguese dialect is still spoken. Also close to Vitoria is Domingos Martins a city with a large population of German descent and offers various German festivals, including Oktoberfest. In addition to wines from these communities (which get limited distribution in the state), there are some small microbreweries such as one outside Santa Teresa in Santa Maria de Jetibá one of the bilingual cities settled by immigrants of German descent from Pomerania (many of them "old lutherans"). However, again there is not much distribution within the state and European-influenced brewing is not as common as in the South of Brazil. The Serra Capixaba (the mountaneous region North of Vitoria) sports many of these communities and you can purchase "productos caseiros" (homemade) European influenced sweets using Brazilian fruits from these areas across the state. Santa Teresa in particular has a lot of production of these sweets and other homemade products, in addition to producing large quantities of vegetables.
Other European influences through tourism and workers are seen, you can for instance buy jamon serrano in supermarkets you would expect and see ads for a "paella valenciana" on signs while driving to beachside towns. Though not a well known regional cusine such as that from Minas Gerais, various states in the Northeast (Pernambuco, Bahia) or the strong european influence in the South of Brazil, Espirito Santo is a place of diverse influences and offering a huge variety of fresh agricultural products.