For the sauce:
-In a medium saucepan, melt 2 TBS butter over medium heat.
-Put 2 cloves of garlic through a press and then add it to the butter. Cook for 1 minute.
-Add 1/8 cup all-purpose flour and ¼ tsp sea salt; cook, stirring frequently, until mixture is pale golden, has a slightly nutty aroma, about 5 minutes.
-Whisking constantly, pour in 2 cups whole milk and whisk until smooth.
-Cook mixture, stirring constantly along the bottom of pan, until boiling.
-Reduce heat to low. Simmer gently, stirring occasionally, until sauce thickens, about 10 minutes.
-Let sauce cool 10 minutes, then whisk in 1 cup grated Gruyere or fontina cheese.
-Stir until well combined then add ½ tsp Dijon mustard and ½ tsp Worcestershire sauce.
-Stir well, then cover cheese sauce and keep warm.
For the roasted broccoli:
-Preheat oven to 450 degrees.
-Cut 1 head of broccoli or 1 bunch broccolini into bite-sized florets.
-On a rimmed baking sheet, toss broccoli, with 3 TBS extra-virgin olive oil; season with sea salt and ground pepper.
-Roast until tender but not mushy, 20 minutes, stirring halfway through.
-Serve topped with cheese sauce.