My go-to is EVOO and pink sea salt. Thats it! Just toss the veggies and stick them in the oven at 400. Sometimes 425. I know some people don’t like to use olive oil at high temps but I have my entire life. So has my mom. And her mom. And so does Ina Garten. So I am sticking with it.
It is hard to roast all veggies on the same pan that have different cook times if you want them all to be optimally crispy. Also, you don’t want to crowd the pan because then they will steam instead of roast.
Don’t toss your veggies too often, especially sweet potatoes! I usually roast them for 40 minutes to an hour and only shake them once. Things like broccoli I tend to stir more often but even then no more than every 10 minutes.
Think through the veggies. Hard ones take longer. Carrots and sweet potatoes tend to take twice as long as broccoli or cauliflower.
You know your oven best. You might need to adjust cooking times and temps because every oven is different. If a recipe says 40 minutes and yours still don’t seem as crispy as you would like, then add cooking time. Roasting is not an exact science.
The more you do it, the easier it gets and the more comfortable you get at knowing when things are done. I promise, I have burned multiple heads of broccoli and served slimy carrots more than I would like to admit.
If roasting from FROZEN, stick them in the oven and let the extra water/ice bits steam off BEFORE you do the olive oil. Give them like 5 minutes, then bring them out and pour a little EVOO and coat in salt. If you do the oil first thing sometimes it can make a slimy mess.
Here is how I get roasted veggies on the table when dinnertime is super chaotic: I roast them during nap time and then do a quick reheat in the oven. I do this the same way I heat leftovers: stick them in the oven cold (all in that one pan that is already dirty) and preheat the oven to 350. By the time the oven is preheated they should be good to go!
I hope some of this was helpful. Remember, its not an exact science, and I am not a professional chef. You might do it totally different and that is ok. This is just what has worked for me.