Block of Walnut with a limb and some rot. Be very cautious when you turn a bowl of this type, it is very easy to snag a tool. Go Slow
Consider how you want the bowl to look as to the grain and defect. Decide which is the top and bottom of the bowl. Start with a faceplate attached to the top of the bowl.
Bowl with outside rough turned and a dovetail recess for a 100mm woodturning chuck on the bottom of the bowl. I alway finish sanding the outside of the bowl, because when you remove the inside material the outside of the bowl will become slightly out of round.
Bowl reversed and the inside rough turned. I power sand these bowls it's a lot easier. You have to be very careful with the defect that you don't snag, keep the leading edge of your sander tipped up away from the defect.
I use a vacuum cup to hold the bowl and remove the dovetail and finish the bottom. Make a small foot on the bottom of the bowl so it does not sit flat and there is a shadow line around the bottom, greatly improves the appearance and adds depth.