In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté for 3-4 minutes until translucent.
Stir in the minced garlic and cook for an additional minute, ensuring it does not burn.
Add the orzo pasta to the pot and toast it lightly for about 2 minutes, stirring frequently.
Pour in the vegetable broth and bring to a boil. Reduce heat to a simmer and add the broccoli florets. Cover and cook for about 8-10 minutes, stirring occasionally until the orzo is cooked and has absorbed most of the liquid.
Once the orzo is tender, stir in the shredded cheddar cheese, Dijon mustard, and heavy cream. Mix until the cheese is melted and everything is combined.
Season with salt, pepper, and optional red pepper flakes to taste. If the mixture is too thick, add a splash more of vegetable broth or cream until desired consistency is reached.
Remove from heat, let it sit for 2 minutes to thicken, then serve warm.
Notes
Serve in deep bowls topped with extra cheddar and fresh parsley.