Test 1 - Curried Roasted Cauliflower

This is a Frankensteined recipe - I just have to track a few things:
A - what is the actual cooking time for ideal done-ness for me (al-dente but with no crunch)
NOTE : I reduced the amount of salt by half and changed 1 tsp of lemon juice to a squeeze
B - Was successful when served to a group - the dish was enjoyed and no improvements suggested. Still do not have the timing set.

1 large (1 lb 12 oz) head cauliflower
1/4 cup olive oil
1 Tbsp curry powder
1/2 tsp salt
1 tsp black mustard seeds
1 tsp cumin seeds
a squeeze of lemon juice
fresh cilantro for garnish

1. Preheat oven to 400F.
2. Cut florets off the cauliflower stem and separate (flowers should be about the circumference of a Loonie).
3. In a large bowl whisk together the oil and the rest of the ingredients.
4. Throw in the cauliflower and toss until well coated.
5. Arrange the oily cauliflower on a cookie sheet, and pour whatever oil mixture is left over the veg.
6. Roast for 20-30 minutes, or until desired done-ness is achieved.
7. Dump into a nice bowl, sprinkle with cilantro, and serve.