Remove the salmon from the refrigerator and let stand at room temperature for 10 minutes. Heat oven to 375 degrees F.
Meanwhile, slice the large lemon in half. With one half, cut into thin slices. The other will be used to squeeze the juice overtop.
Lay out two sheets of aluminum foil. Place one salmon filet on each piece of foil and rub generously with extra virgin olive oil.
Carefully fold up the edges of the foil to form a "boat" around the salmon. This way, the lemon juice & oil won't spill out!
Squeeze the second half of the lemon overtop the salmon filets. Add two lemon slices, the rosemary sprigs, and 1 tsp of capers on each. Add the minced garlic evenly between both pieces of salmon. Sprinkle with kosher salt and black pepper to finish.
Wrap the salmon completely in the foil, so the entire piece is enclosed. However, leave a little room inside for the heat to circulate - so don't close it up too tightly!
Bake the salmon for 10-15 minutes, depending on your preference of done-ness. Check at 10 minutes to see if the thickest part of the salmon is cooked through. Cooking time will vary between oven & thickness!
Remove the salmon from the oven once cooked. Serve inside the foil packets with rice or veggies on the side! Enjoy!