Truffle–Ricotta Panna Cotta with Lamb’s Lettuce

2 cups white vinegar
1 cup water
1 cup sugar
1/4 cup sea salt
4 cloves garlic
1 1/2 teaspoons coriander seeds
1 1/2 teaspoons mustard seeds
1 1/2 teaspoons whole black pepper
8 sprigs tarragon
8 sprigs thyme
1 cup julienned radishes
4 sheets gelatin
2 cups heavy cream, divided
1 cup ricotta
Lemon juice and zest to taste
Salt to taste
Truffle oil to taste
3/4 cup mâche or lamb’s lettuce

Combine the white vinegar, water, sugar, salt, garlic, coriander seeds, mustard seeds, and black pepper in a small saucepan. Bring to a boil over high heat. Reduce to a simmer and continue simmering for 5 minutes. Turn off the heat.

Wrap the tarragon and thyme in a piece of cheesecloth and tie with string. Place in a canning jar or plastic container with the radishes. Pour the hot vinegar mixture over the radishes and let cool for 1 hour on the counter. (Can be made several days ahead. Refrigerate until needed.)

Submerge the gelatin in a large bowl of ice water. Bring 1 cup of the cream to a simmer in a small sauce pot over medium-high heat. Remove the gelatin from the water and squeeze gently to remove excess water. Add to the hot cream; whisk until smooth and the gelatin is dissolved. Remove from the heat and reserve.

Place the ricotta in a food processor. With the machine running, slowly add the remaining cream; continue blending until the mixture is creamy and smooth. Add to the warm cream, whisking until combined. Strain through a fine-mesh sieve. Add lemon juice, lemon zest, salt, and truffle oil to taste. Pour into 4-ounce ramekins or jars and refrigerate until set, at least six hours and up to overnight.

Remove the panna cottas from the refrigerator 1 hour before serving. Garnish with lamb’s lettuce and pickled radishes.