Preheat oven to 375 degrees Fahrenheit (190 degrees Celsius).

In a large skillet, heat oil. Sauté shallots until beginning to brown, about 10–15 minutes. Add garlic. Add spinach in handfuls until it’s all wilted. Season with 1/2 teaspoon salt and pepper. Allow to cool.

With a sharp paring knife, cut a slit in the thickest part of a slice of salmon and carefully stuff it with about a tablespoon of the cooled spinach mixture. Continue until all the fillets are stuffed, then season the salmon with remaining one teaspoon salt, garlic powder, dried parsley, and dried basil.

Bake for 18–22 minutes, or until desired doneness is reached.