Bring a large pot of water to boil and cook pasta according to package instructions.
Gently wash mushrooms to remove any dirt.
Slice each mushroom into about 4 pieces.
Add to a pan with the broccoli, add about 1/2 inch of water, cover, and let steam for about 5-7 minutes.
Prepare the sauce by mincing the garlic.
Add the garlic to a large pot with the olive oil and cook until the garlic starts to brown.
Stir in the flour and whisk to get rid of any clumps.
Slowly stir in the almond milk and continue to whisk.
Add the lemon juice and lemon zest if using.
Reduce heat to low and let simmer until the sauce has thickened. If the sauce doesn’t thicken to your desired consistency, whisk in an additional tbsp of flour.
Add the salt and pepper and stir.
For an ultra creamy sauce, transfer to a blender or use an immersion blender and process until completely smooth.
Add the mushrooms, broccoli, and sauce to the cooked pasta.
Top with additional salt, pepper, or red pepper flakes if desired and enjoy!