customstartexample_Executor.java

package i.gabrielcosta.customstartexample;

import android.content.Context;
import java.io.Serializable;

/**
 * Created by gabrielcosta on 26/08/17.
 */

public interface Executor extends Serializable {

  void execute(final Context context);

}

customstartexample_MainActivity.kt

package i.gabrielcosta.customstartexample

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.widget.Button
import android.widget.Toast

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        val button = Button(this)
        button.text = "Open Normal Activity"
        setContentView(button)
        button.setOnClickListener {
            openNormalActivity()
        }

    }

    private fun openNormalActivity() {
        startNormalActivity(baseContext, Executor { context ->
            Toast.makeText(context, "Executado", Toast.LENGTH_LONG)
                    .show()
        })

    }
}

customstartexample_NormalActivity.kt

package i.gabrielcosta.customstartexample

import android.content.Context
import android.content.Intent
import android.os.Bundle
import android.support.v7.app.AppCompatActivity

fun startNormalActivity(context: Context, executor: Executor) {
    val intent = Intent(context, NormalActivity::class.java)
    intent.putExtra(NormalActivity.EXTRA_EXECUTOR, executor)
    context.startActivity(intent)
}

class NormalActivity : AppCompatActivity() {

    companion object {
        val EXTRA_EXECUTOR = "EXTRA_EXECUTOR"
    }

    lateinit var executor: Executor

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_normal)
        extractExecutor()
    }

    private fun extractExecutor() {
        if (intent.hasExtra(EXTRA_EXECUTOR)) {
            executor = intent.getSerializableExtra(EXTRA_EXECUTOR) as Executor
            executor.execute(this)
        }

    }

}

Amazing example.