Keep an interruption log
For five working days, note every decision that comes back to you. Record the question, why the person could not decide, and what information you used.
Find the repeat
Group similar interruptions. Look for missing access, unclear standards, pricing exceptions, and approvals that only you can give. Start with one frequent, reversible decision.
Write the boundary
Give the owner a rule, a limit, and an escalation condition. A useful rule explains what they can decide, what they must record, and when they must involve you.
Review before expanding
Inspect a few decisions together. Improve the rule where it breaks. Delegate broader authority after the person and the process demonstrate that they can handle it.