Combine garlic, avocado oil, soy sauce, rosé wine, and ginger in a Pyrex dish. Add the salmon steaks and allow to marinate in the refrigerator for one hour.
Prepare a gas or charcoal grill to medium heat.
On the stove top in a medium sauté pan, add olive oil and heat to medium high. Then add the string beans and sugar snaps. Season with salt and pepper, and sauté for 3 minutes. Add 1/4 cup cold water, then add 2 tablespoons of the butter, cover with a lid, and turn off heat.
Prepare the salmon: Remove the salmon from the marinade, reserving the remaining marinade. Pat the salmon dry, and place it skin-side down on the grill and cook for about 5 minutes until it easily releases from the grill. Flip and continue cooking for 1 minute more for medium doneness. Transfer the salmon to a family-style plate.
Meanwhile, add the reserved marinade to a sauce pan and place over medium heat. Once it starts bubbling, add the remaining 2 tablespoons of butter, give it a stir to help it melt, then turn off the heat.
To serve, transfer the sauce to a small bowl and place on the family-style dish with the salmon, along with the snap peas and string beans.