Heat lightly oiled skillet over med-high; pat meat dry, season with salt/pep + sear undisturbed 2-3 min until browned; flip meat over + sear 2-3 min more for medium-rare (for more well done, add 1-2 min per side) then let meat rest; slice thinly + set aside

Wipe mushrooms clean + thinly slice; heat 1 tbsp oil in skillet over med-high + sauté pepper mix + mushrooms with salt/pep 4-5 min or until soft + starting to brown

Cut baguette in half, slice lengthwise; assemble sandwiches with 2 slices cheese, beef + veggies; toast in a lightly oiled skillet 3-4 min per side until golden + cheese melts—yum!