1. Preheat the oven to 375 degrees.
2. Peel and cut the carrots into even size pieces of your choosing, and drop them into a large bowl.
3. Add the olive oil and salt into the bowl with the carrots, and toss the ingredients together.
4. Prepare your sheet pan, and spread the carrots from the bowl evenly on the pan. Slice the stick of butter into pats and place them among the carrots, keeping in mind to spread the pats out evenly across the pan.
5. Roast the carrots for 25-30 minutes, or until fork-tender. Once cooked, remove from the oven and set aside to cool. 
6. Remove the basil leaves from the stem and Chiffonade by stacking the leaves, and rolling like a cigar, before slicing the into thin strips. 
7. Once the carrots are cooled, but still warm, add to a large bowl and sprinkle in your basil and mix together before serving.