As Doug in #2 said.
Waterjet should cut lots of nested blanks with very little waste, then finish machine as appropriate.
Seems thick for laser.
If the parts are about a4 size, about 5 minutes / side/part, to do the profiles.
Endless ways to make it efficient.
Maybe the jet could leave tabs, and the part could be undercut and finished all in one.
In alu and CI this should work, perhaps with live clamping (that can move out of the way).
Perhaps the slots and chamfers can be done with the part flat.
Custom tool maybe for chamfers, or slots cut from side, but only one op, with last op cutting it free from tabs.
Or cut 10, then rack them back side up, and do the slots and chamfers for all 10, aligned via jig pins.
You could do the chamfers from behind, via a suitable cutter, if the radius / width permits depending on material.
As everyone said, and as always.
How many ?
Desired tolerance, ballpark ?
Aka 15 mm radius and looks good cosmetically, is a good definition.
Desired speed ?
Your post seemed to indicate == 10 units at 2 days, ballpark.
Most here would want the job to move at 5 units per hour at 30$ each, 150$ machining shop rate.
And many here expect exact 3d curve tolerances and finishes defined by Rx values.
But those guys are perfectly willing to spend 500$ in materials, jigs, and 300$ in time to make up a production fixture.
They would also expect to make at least 30-50-100 pieces at 30$ each.
With any basic probing for location, I would expect to make about 10 parts per hour on any semi decent vmc.
Size a4 or less, easy material, cosmetics not critical.
4 ops, max, 2-3 if custom tools are appropriate, depending.
After about 4 hours of nre non recurring engineering charge, at 150$, 600$, or so.
Somewhere around 10-15-20 pcs / hr are possible, in brass/ci/alu if the job is big enough and worth investing effort in.
It´s somewhat straightforward to gear up to make 2000 in easy materials (alu) and no critical tolerances.
Your post re:welding indicates steel.
It may be hard or impossible to do the near-end slot in steel, from up front, as the upfront piece may likely foul the spindle.
If the height is about 150-200 mm as seems likely, only a solid carbide cutter with small tip would work, with such a long overhang.
From reverse side, a rougher and a finish cutter might make a nice curved slot in good order.
Depending on radi, it might be impossible to feed them through the slot.
A horizontal traditional mill might chew the front slot and radius quickly.
It would either need accepting whatever radius they have in tooling, or paying for a custom tool, typically 500€+, and 3 weeks to get one.
Please indicate quantity, materials, accuracy tolerance, and approx. desired time and costs.