Creamy & Cheesy Baked Salmon

Ingredients:
1 garlic clove
1/4 cup salted butter amzn.to/4e8MaEy
3 tbsp. all purpose flour amzn.to/3Afm8BC
2 cups whole milk amzn.to/4heWspD
6 oz. shredded parmesan cheese amzn.to/3NFH5c4
1/4 tsp. salt & more for seasoning the salmon amzn.to/48jXJaR
1 salmon fillet (~1.9 lbs.) amzn.to/4e0gIIx
Juice of 1/2 lemon