Bring a pot of water to a boil. Prepare an ice water bath. In batches by type, blanch the radishes, English peas and snow peas in the boiling water for 1 minute per batch. Transfer each batch to the ice water to stop the cooking process, then transfer to a colander to drain. Cut the snow peas into julienne strips. Transfer the blanched vegetables to a bowl and set aside.
Heat a cast-iron pan over medium-high heat. Season the pork chops with the coriander, cumin and some salt and pepper.
Add the oil to the pan and heat until smoking. Add the pork chops, reduce the heat to medium and cook until caramelized on one side, about 3 minutes. Flip the chops and cook until caramelized on the other side, another 3 minutes.
Reduce the heat to low and add the garlic, tarragon and 3 tablespoons of the butter. Cook, basting the pork with the butter (be careful not to burn the butter, though it will brown lightly), until the pork reaches an internal temperature of 135 degrees F for medium, about 4 minutes. Transfer the chops to a baking sheet and keep warm in the oven while you make the sauce and finish the vegetables.
Drain off half of the butter, add the leeks and saute until softened, 3 to 4 minutes. Add the white wine and cook, scraping up the brown bits from the bottom of the pan. Stir in the chicken stock and mustard and cook for a few minutes until slightly reduced. Add the remaining 2 tablespoons butter to form a pan sauce and season with the champagne vinegar. Add the reserved vegetables to warm in the sauce while it simmers to reduce, about 5 minutes. Add salt and pepper as necessary.
Serve the vegetables and sauce with the pork and garnish with dill.