Preheat oven to 425 degrees.
In large, heavy pan, lightly brown diced strips of bacon.
Remove bacon from pan when lightly browned, set aside.
Remove much of the bacon grease from the pan (a little is perfect - but you don't want too much- just enough to glisten across the bottom of the pan, but not enough to pool up.)
Add broccoli, cauliflower, and garlic to pan.
Drizzle with lemon juice, olive oil, salt and pepper, and herbs - toss well to coat evenly.
Place in oven and roast for 30 minutes - until vegetables have started to brown and have reduced in size by about a third.
Add bacon to pan, and sprinkle vegetables with parmesan.
Roast for another 5-10 minutes, until parmesan is golden and vegetables have browned bits and are tender to the touch - but aren't too soft. For softer vegetables, add 10 minutes oven time before adding bacon and parmesan.
Remove from oven and serve immediately.