Heat oil and rosemary leaves in a large pot over low heat.

Add nuts and stir to coat with oil. Toast nuts for about 3 minutes (or until fragrant and golden brown). Stir in salt.

Spread nuts on a rimmed baking sheet or on a piece of parchment paper to cool.

Once the completely cool, store the nuts in an airtight container for up to 1 week (it's best to keep them fresh in the refrigerator).