Heat the olive oil over medium heat in your largest skillet. Add garlic and sauté for about 20 seconds. Add broccoli, portobellos and 1/4 teaspoon salt and reduce heat to medium low. Cook, turning occasionally, until broccoli is completely tender and melting, up to 45 minutes. Add a little more olive oil during the process if it seems advisable.
Add sausage to the pan and continue to sauté, breaking it up until meat is cooked through.
Divide between two bowls. Sprinkle with flaky salt, freshly ground black pepper and chili flakes, if desired.