New Twiddle

components.menu.item\.js

import Component from '@glimmer/component';

export default class extends Component {
}

components.menu\.js

import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';
import { guidFor } from '@ember/object/internals';

export default class extends Component {
  get id() {
    return guidFor(this); 
  }
}

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

helpers.or\.js

import { helper } from '@ember/component/helper';

export default helper(function or(params/*, hash*/) {
  return params.find(parm => parm)
});

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>
{{! play with this by adding id="1" }}
<Menu as |menu|>
  <menu.Item>hi</menu.Item>
</Menu>

templates.components.menu.item\.hbs

<li>{{yield}}</li>

templates.components.menu\.hbs

id: {{this.id}}
<ol id={{or attributes.id this.id}}>
  {{yield (hash Item=(component "menu/item" id=(or attributes.id this.id)))}}
</ol>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}