This can be a bow. I would not skimp on sinew, and I would not pish the limits of draw weight.
1. Decrowning the stave. I would get the back flat, then kind of narrow the flattened back portion by rounding THOROUGHLY or even beveling off the side of the back to reintroduce a slight crown. Make sure that sinew is going to work!
2. Roughing out the front profile
3. Get it to floor tiller .... Don't even think about trying to get it braced, we're just talking bending a couple inches and evenly. Basically just establish your thickness taper.
4. Do all your steam bending to straighten at thing out. Clamp it to something and let it dry ..... For a long time. I find ERC wants to wander on me when drying.
5. Sinew that thing and don't be stingy. I would get two good courses on there, making sure to cover the whole back, and also introduce a slight crown with the sinew. ERC is quite brittle so again, make sure you at least cover the whole back. Even if most of the sinew is in the center of the limb.
6. Dry that thing out again. Don't rush. If you're not sure, wait longer.
7. Buy helmet and beer.
8. Tiller.
That's the long and the short of it in my opinion.