Seems I’ve heard where the UK ruling on something is appealed to a higher authority outside the UK and that, by itself, proves the UK can be “ruled” by Europeans, not Brits.
There isn’t any such case - the european Court of Justice does not, however, have any power to strike down national law; this is a task for the national courts.
The UK is not “ruled” by Europeans, nor by European institutions.
Firstly - the UK as part of the EU is part of the various EU institutions:
1. remember Nigel Farage? He was elected as a Member of the European Parliament. He has been an MEP for years (he was first elected as MEP from the UKIP). The UK has 73 seats in the europarliament. This is analogous to the US congress in that seats are allocated as per population. No one European country dominates this - even Germany with 83 million is only little less than 20% of the population. Furthermore the euparliament parties form cross-country coalitions to get the parties ways.
2. the eu council is the council of heads of government, like Boris. It has veto powers. This is analogous to the US senate only where all the senators have to agree or nothing gets passed. This veto power would not work for a country, but the EU is a confederation of countries, so it works and it is better for the countries to agree unanimously in a confederation.
3. The eu commission is analogous to the civil service - each country proposes one member to the civil service.
4. the ecj is again - one member, one justice.
so the UK has never been “ruled” - the UK is part of those that rule the EU.