Bring water to boiling in a large pot and add noodles, boiling 3-4 minutes, just to get them started. Strain and set aside.
Small dice bacon and sauté until crispy in a large skillet. Remove bacon and transfer to a paper towel-lined plate. Drain bacon fat from pan and save for another use. Return pan to medium heat. Melt butter and sauté garlic for 30 seconds. Add flour and whisk to blend. Cook for 1 minute then add milk and cream. Whisk to blend and let simmer for 3 minutes. Add salt, pepper, sage, rosemary and mustard. Simmer 2 more minutes.
Add all 3 cheeses; stir until melted then fold in noodles and sautéed bacon. Pour into greased 9" x 13" pan and top with breadcrumbs. Drizzle with melted butter and bake 20-25 minutes.
Notes
Make mac ‘n’ cheese ahead of time so it’s ready to go when you are!