Preheat the oven to 425°.
In a large bowl whisk together the mustards, brown sugar, garlic, vinegar, olive oil, soy sauce and rosemary until combined.
Transfer the mixture to a plastic zip bag and submerge the tenderloins into the mixture and marinate for 30 minutes.
Next, remove the pork tenderloins and add them on to a cookie sheet tray pan lined with parchment paper and season the top of the pork with salt and pepper.
Roast in the oven at 425° for 20 to 25 minutes or until browned and cooked through out.
Serve alongside vegetables and potatoes.