In a large sauté pan, melt the butter over medium-high heat until brown.
Add the turnips, cut side down, and the snap peas. Cook for 3–4 minutes until the veggies begin to brown. Make a small space on the bottom of the pan and add the garlic. Cook until the garlic is golden brown, about 3 minutes.
Toss to combine and add the garum and wine. Simmer until the sauce is thick and coating the veggies. Remove from the heat and transfer to a serving platter.
In a bowl, combine the herbs and orange segments and toss to combine with the olive oil. Just before serving, scatter the herb salad over the veggies.