Italians are fond of preserving vegetables—and fruit—in a sweet-and-sour brine known as agrodolce. Sweet peppers are a classic example, but I like this somewhat more unusual combination of crunchy carrots and sliced fennel bulb. Use a mix of colored carrots—gold, orange and red—if you can find them. The darker ones turn the brine a pretty shade of sunset pink.

2 C. (437 g) water
Juice of 2 lemons
2 pounds (907 g) fennel bulbs, plus 4 small fronds
2 pounds (907 g) carrots, peeled
2 C. (437 g) white wine vinegar
2 C. (437 g) apple cider vinegar
2 C. (400 g) sugar or vanilla sugar
2 T. fine sea salt
1 tsp. whole black peppercorns
1 tsp. whole fennel seeds

Combine the water and lemon juice in a bowl. Cut the tops off the fennel bulbs. Cut each bulb into quarters and each quarter into thin wedges. Drop each wedge in the lemon water as you go to keep it from browning. Cut the carrots into 2-inch sticks, and cut any large pieces in half or into quarters lengthwise to yield bite-size pieces. Add the carrots to the lemon water. Combine the vinegars, sugar, salt, peppercorns and fennel seeds in a large, deep saucepan over medium-high heat. Bring the brine to a boil, stirring occasionally to make sure the sugar dissolves. Drain the fennel and carrots and add them to the boiling water. Cover the pot, turn off the heat and let sit for 5 minutes. Place a fennel frond in the bottom of each jar. Pack the vegetables into the jars, taking care to get a mix of vegetables and some spices in each one. Pour the hot brine over the vegetables, leaving ½ inch headspace. Use a bubble remover or a clean chopstick to get rid of any bubbles. Screw the lids on tightly, and process for 10 minutes in a boiling-water bath. Store the sealed jars in a cool, dark place and let the vegetables cure for at least 1 week before serving. They will keep for up to 1 year, though they may eventually lose their crisp texture. Refrigerate any jars that fail to seal properly and enjoy those first.